JP2016056280A - Surface-treated inorganic filler, method for producing the inorganic filler, and resin composition containing the inorganic filler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-treated inorganic filler capable of forming an insulation layer to be formed with a conductor layer having high peel strength even if roughness is low, and a resin composition comprising the surface-treated inorganic filler.SOLUTION: Provided is a surface-treated inorganic filler applied with plasma treatment after surface treatment with a silazane compound. Also provided is a resin composition comprising the surface-treated inorganic filler, an epoxy resin and a hardening agent.SELECTED DRAWING: None

Description

  The present invention is obtained from a surface-treated inorganic filler, a resin composition suitable for forming an insulating layer (particularly an interlayer insulating layer) of a circuit board such as a multilayer printed wiring board using the inorganic filler, and the resin composition. The present invention relates to an adhesive sheet such as a resin sheet or a prepreg, and a circuit board on which an insulating layer is formed of a cured product of the resin composition.

  In recent years, with the miniaturization and high performance of electronic devices, circuit boards are required to have fine wiring and further lower the thermal expansion coefficient. As means for reducing the thermal expansion of the insulating material, a method of increasing the filling of an inorganic filler such as silica is known. As means for highly filling silica in a resin composition, a method of surface-treating silica with various coupling agents is known. For example, in Patent Document 1, in a resin composition, by using an inorganic filler surface-treated with a silazane compound and then surface-treated with a silane coupling agent, the laminating property particularly when used in the form of an adhesive sheet is used. There is disclosed a method that enables formation of a conductor layer having a high peel strength even when the surface roughness of the insulating layer obtained by curing it is excellent, even when the surface roughness of the insulating layer is low.

  Moreover, in patent document 2, the problem of the fall of the fluidity | liquidity by the raise of the viscosity of the epoxy resin composition when a silica is contained and the aggregation of silica are solved by performing a plasma treatment on the surface of silica. However, the physical properties of the cured product such as the surface roughness of the cured product of the epoxy resin composition are not mentioned.

JP 2012-255174 A JP 2010-275334 A

  The present invention has been made in view of the above circumstances, and the problem to be solved can be suitably used for forming an insulating layer of a circuit board, and in particular, insulation obtained by curing it. A surface-treated inorganic filler, a method for producing the inorganic filler, and the inorganic filler for obtaining a resin composition capable of forming a conductor layer having a high peel strength even when the roughness of the layer surface is low. It is in providing the resin composition to contain.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has incorporated a surface-treated inorganic filler that has been subjected to a plasma treatment after the surface treatment of the inorganic filler with a silazane compound, together with an epoxy resin and a curing agent. In order to complete the present invention, the present inventors have found that a resin composition can be a resin composition that enables the formation of a conductor layer having a high peel strength even when the roughness of the insulating layer surface obtained by curing the resin composition is low. It came. That is, the present invention includes the following contents.

[1] A surface-treated inorganic filler that is subjected to a plasma treatment after a surface treatment with a silazane compound.
[2] The surface-treated inorganic filler according to the above [1], wherein the plasma treatment is a treatment in which argon plasma is irradiated for 30 seconds or more under a condition of 100 W or more.
[3] The silazane compound is hexamethyldisilazane, 1,3-divinyl-1,1,3.
3-tetramethyldisilazane, octamethyltrisilazane, hexa (t-butyl) disilazane, hexabutyldisilazane, hexaoctyldisilazane, 1,3-diethyltetramethyldisilazane, 1,3-di-n-octyltetra Methyldisilazane, 1,3-diphenyltetramethyldisilazane, 1,3-dimethyltetraphenyldisilazane, 1,3-diethyltetramethyldisilazane, 1,1,3,3-tetraphenyl-1,3-dimethyl Disilazane, 1,3-dipropyltetramethyldisilazane, hexamethylcyclotrisilazane, hexaphenyldisilazane, dimethylaminotrimethylsilazane, trisilazane, cyclotrisilazane, and 1,1,3,3,5,5-hexa One selected from the group consisting of methylcyclotrisilazane Is 2 or more, a surface-treated inorganic filler of the above-mentioned [1] or [2].
[4] The surface-treated inorganic filler according to any one of [1] to [3], wherein the average particle diameter is 0.01 to 5 μm.
[5] The surface-treated inorganic filler according to any one of [1] to [4], wherein the inorganic filler is silica.
[6] The surface-treated inorganic filler according to any one of [1] to [5], wherein the inorganic filler is a spherical particle.
[7] The surface-treated inorganic filler according to any one of [1] to [6], which is used for a resin composition for forming an insulating layer of a circuit board.
[8] A method for producing a surface-treated inorganic filler, comprising subjecting the inorganic filler to a surface treatment with a silazane compound and further subjecting the inorganic filler to a plasma treatment.
[9] (A) A resin composition comprising the surface-treated inorganic filler according to any one of [1] to [7], (B) an epoxy resin, and (C) a curing agent.
[10] The resin composition according to [9], wherein the content of the surface-treated inorganic filler is 50% by mass or more when the nonvolatile component in the resin composition is 100% by mass.
[11] The resin composition according to [9] or [10], further comprising (D) a curing accelerator.
[12] The resin composition according to any one of [9] to [11], further comprising (E) a thermoplastic resin.
[13] An adhesive sheet in which a layer of the resin composition according to any one of [9] to [12] is formed on a support.
[14] A prepreg obtained by impregnating a sheet-like fiber base material with the resin composition according to any one of [9] to [12].
[15] A circuit board including an insulating layer formed of a cured product of the resin composition according to any one of [9] to [12].

  When an insulating layer of a circuit board (particularly an insulating layer of a multilayer printed wiring board) is formed of an epoxy resin composition containing a large amount of an inorganic filler, the peel strength of the conductor layer usually formed on the surface of the insulating layer is lowered. There is a tendency. However, the insulating layer obtained from the epoxy resin composition containing a large amount of the surface-treated inorganic filler of the present invention can form a conductor layer having high peel strength while keeping the surface roughness low. Therefore, by using the resin composition containing the surface-treated inorganic filler of the present invention, for example, thermal expansion coefficient, dielectric properties, heat resistance, toughness, slidability, wear resistance, dimensional stability, etc. While improving various characteristics, it is possible to realize an insulating layer (particularly an interlayer insulating layer) advantageous for forming fine wiring, and as a result, it becomes possible to form a highly functional and reliable circuit board having fine wiring. .

Hereinafter, the present invention will be described with reference to preferred embodiments thereof.
[(A) Surface-treated inorganic filler]
The surface-treated inorganic filler of the present invention refers to an inorganic filler that has been surface-treated with a silazane compound and then subjected to plasma treatment. The surface-treated inorganic filler of the present invention, for example, in a resin composition for forming an insulating layer of a multilayer printed wiring board, reduces the thermal expansion coefficient of the insulating layer, improves dielectric properties, and improves heat resistance. , To improve toughness, improve slidability, improve wear resistance, improve dimensional stability, impart thixotropy, impart dilatancy, etc. .

  Examples of the inorganic filler to be surface-treated include silica (spherical silica, amorphous silica, fused silica, crystalline silica, synthetic silica, etc.), alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, water Magnesium oxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, etc. Is mentioned. One or more inorganic fillers can be used, and silica is particularly preferable. In addition, the surface-treated inorganic filler is formed from a resin composition, an improved filling property in a resin varnish in which the resin composition is dissolved or dispersed in an organic solvent, a fluidity improvement due to a decrease in the viscosity of the resin varnish, and a resin composition. From the viewpoint of suppressing increase in surface roughness of the insulating layer to be formed, spherical particles are preferable. Note that the sphericity of the inorganic filler is substantially the same before and after the surface treatment. Therefore, the inorganic filler to be surface-treated is preferably spherical particles.

  The average particle diameter of the surface-treated inorganic filler is not particularly limited, but is preferably 5 μm or less, more preferably 3 μm or less, further preferably 1 μm or less, and particularly preferably 0.7 μm or less. When the average particle diameter of the surface-treated inorganic filler exceeds 5 μm, the peel strength of the conductor layer tends to decrease when the conductor layer is formed by plating on the insulating layer formed from the resin composition. In addition, when the average particle diameter of the surface-treated inorganic filler is too small, when the resin composition containing the surface-treated inorganic filler is used as a resin varnish, the viscosity of the varnish increases and the handleability tends to decrease. Therefore, the average particle diameter of the surface-treated inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, and further preferably 0.1 μm or more. Even if the average particle size of the surface-treated inorganic filler is 5 μm or less, if it contains a large amount of coarse particles, irregularities derived from the coarse particles are produced during the roughening treatment, and plated copper is plated on the irregularities when the conductor layer is formed by plating. Permeates, and it becomes easy to short circuit between the miniaturized conductors. Therefore, the inorganic filler preferably has a maximum particle size of 10 μm or less.

The average particle size and the maximum particle size of the surface-treated inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is created on a volume basis with a laser diffraction particle size distribution measuring device, the median diameter (50% value) is the average particle diameter, and the 5% value is the maximum particle diameter. Measured in As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As a laser diffraction type particle size distribution measuring apparatus, LA-500 manufactured by Horiba, Ltd. or the like can be used.

Examples of the silazane compound used for the surface treatment include hexamethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, octamethyltrisilazane,
Hexa (t-butyl) disilazane, hexabutyldisilazane, hexaoctyldisilazane, 1,3-diethyltetramethyldisilazane, 1,3-di-n-octyltetramethyldisilazane, 1,3-diphenyltetramethyldi Silazane, 1,3-dimethyltetraphenyldisilazane, 1,3-diethyltetramethyldisilazane, 1,1,3,3-tetraphenyl-1,3-dimethyldisilazane, 1,3-dipropyltetramethyldi Examples thereof include silazane, hexamethylcyclotrisilazane, hexaphenyldisilazane, dimethylaminotrimethylsilazane, trisilazane, cyclotrisilazane, 1,1,3,3,5,5-hexamethylcyclotrisilazane and the like. The silazane compound can use 1 type (s) or 2 or more types, Especially, hexamethyldisilazane is preferable.

  The surface treatment of the inorganic filler with the silazane compound can be performed, for example, by adding and spraying the silazane compound and stirring for 5 to 15 minutes while stirring and dispersing the untreated inorganic filler at room temperature with a mixer. . In addition, a commercially available inorganic filler surface-treated with a silazane compound (inorganic filler with silazane compound treatment) can be used. Such a commercially available product is directly subjected to the plasma treatment described later. In order to firmly adhere the silazane compound to the inorganic filler, after the above operation, the inorganic filler may be taken out from the mixer and allowed to stand for more than one day, or after the silazane compound is added and sprayed. A slight heat treatment may be performed after the stirring operation. The light heat treatment is, for example, a heat treatment at a temperature of about 40 to 80 ° C. for about 1 to 12 hours. In order to uniformly deposit the silazane compound on the inorganic filler, an organic solvent may be added and mixed after the addition spray of the silazane compound. As the mixer, known mixers can be used, for example, blenders such as V blenders, ribbon blenders and bubble cone blenders, mixers such as Henschel mixers and concrete mixers, ball mills, etc., and mixers are preferably used. Is done.

The treatment amount of the silazane compound is preferably 0.005 to 2 parts by mass and more preferably 0.1 to 1 part by mass per 100 parts by mass of the inorganic filler. The amount of carbon bonded to the surface of the inorganic filler surface-treated with the silazane compound is approximately 0.02 to 0.30 mg / m ² , although it varies depending on the particle size of the inorganic filler. It is preferable. If the carbon amount per unit area is 0.02 mg / m ² or more, the surface modification of the inorganic filler with the silazane compound is sufficiently performed. Further, the upper limit value of the carbon amount is not particularly limited, but generally falls within 0.30 mg / m ² or less. Here, the “carbon amount per unit area” is measured by the following method.

<Measurement of carbon amount per unit area>
Using 5 g of an inorganic filler surface-treated with a silazane compound as a sample, put the sample and 24 g of IPA (isopropyl alcohol) in a centrifuge tube, stir the suspension to suspend the solid content, and apply 500 W ultrasonic waves. For 5 minutes. Thereafter, solid-liquid separation is performed by centrifugation, the supernatant is removed, 24 g of IPA is added, and the mixture is stirred to suspend the solid content, and 500 W ultrasonic waves are irradiated for 5 minutes. Thereafter, solid-liquid separation is performed by centrifugation, the supernatant is removed, 24 g of IPA is added, and the mixture is stirred to suspend the solid content, and 500 W ultrasonic waves are irradiated for 5 minutes. The solid content is dried in a desiccator at room temperature for 96 hours, 0.2 g of this dried sample is accurately weighed in a measurement crucible, and a combustion aid (3.0 g of tungsten, 0.3 g of tin) is added to the measurement crucible. . Set the measuring crucible on the carbon analyzer and measure the carbon content. For the carbon analyzer, EMIA-320V manufactured by HORIBA, Ltd. can be used. A value obtained by dividing the carbon amount thus measured by the specific surface area is defined as the carbon amount per unit area. The specific surface area of the inorganic filler by the BET flow method and an inorganic filler 0.5g as Sample (1-point method), the powder surface is temporarily adsorb N ₂ molecules, detecting the desorbed N ₂ molecular weight Thus, the surface area of the sample is calculated. Specifically, after heating and degassing at 300 ° C. for 15 minutes, rapid cooling (using liquid nitrogen) is performed while flowing nitrogen gas for 5 minutes to adsorb nitrogen. Thereafter, the temperature is returned to room temperature, the gas is desorbed, the surface area is calculated from the attached / detached amount, and the specific surface area is derived by dividing the obtained surface area by the sample amount. For measurement, Macsorb HM-2201FS manufactured by Mountaintech or the like can be used.

In the present invention, plasma treatment is further applied to the inorganic filler surface-treated with the silazane compound. The plasma treatment is not particularly limited as long as the treatment can irradiate the surface of the inorganic filler surface-treated with the silazane compound. For example, an inorganic filler in which the gas flowing between the electrodes is sequentially brought into a plasma state by discharging between the opposing electrodes under atmospheric pressure or near atmospheric pressure, and the resulting plasma is surface-treated with a silazane compound. The gas flowing between the electrodes is sequentially plasma by discharging between the opposing electrodes at a low pressure, that is, at a pressure of 500 Pa or less (preferably 0 to 100 Pa). And a treatment (low-pressure (vacuum) plasma treatment) in which the obtained plasma is irradiated onto the inorganic filler surface-treated with the silazane compound. The foreign matter becomes a gas by the plasma treatment, but low pressure (vacuum) plasma treatment is preferable from the viewpoint of removing the gas derived from the foreign matter. As the gas to be in a plasma state, Ar gas, N ₂ gas, O ₂ gas, H ₂
Examples thereof include a single gas composed of one kind selected from the group consisting of gas and He gas, or a mixed gas composed of two or more kinds selected from the above group. Ar gas, He gas, and N ₂ gas are preferable.

  In the atmospheric pressure plasma treatment, the current discharged between the electrodes when generating plasma is preferably 500 W or more, more preferably 1,000 W or more, from the viewpoint of generating a sufficient amount of plasma. The upper limit is not particularly limited, but generally 10,000 W or less is preferable. The treatment temperature is preferably 0 to 40 ° C., more preferably 15 to 30 ° C. from the viewpoint of having sufficient reactivity and preventing aggregation of the inorganic filler due to overheating. Further, the treatment time is preferably 5 seconds or more, more preferably 10 seconds or more, and further preferably 30 seconds or more. The upper limit of the processing time is not particularly limited, but generally 300 seconds or less is preferable.

  In the low-pressure (vacuum) plasma treatment, the current discharged between the electrodes when generating plasma is preferably 50 W or more, more preferably 100 W or more, from the viewpoint of generating a sufficient amount of plasma. The upper limit is not particularly limited, but generally 1,000 W or less is preferable. The treatment temperature is preferably 0 to 40 ° C., more preferably 15 to 30 ° C. from the viewpoint of having sufficient reactivity and preventing aggregation of the inorganic filler due to overheating. Moreover, as processing time, 30 seconds or more are preferable, 45 seconds or more are more preferable, and 60 seconds or more are further more preferable. The upper limit of the processing time is not particularly limited, but generally 600 seconds or less is preferable.

  Note that low-pressure (vacuum) plasma treatment is preferable because impurities generated during the plasma treatment can be removed. That is, when impurities of organic compounds are attached to the inorganic filler, the impurities are vaporized by plasma treatment, but in low pressure (vacuum) plasma treatment, the vaporized impurities are sucked into a vacuum pump (with a trap provided). If it is trapped), it is removed. Therefore, the inorganic filler treated by the low-pressure (vacuum) plasma treatment is advantageous in terms of stabilizing the physical properties of the resin composition of the present invention and the cured product thereof described below because the influence of impurities is reduced. .

[Resin composition]
The present invention provides a resin composition comprising such “(A) a surface-treated inorganic filler that has been subjected to a plasma treatment after a surface treatment with a silazane compound” (hereinafter also abbreviated as “the surface-treated inorganic filler of the present invention”). (Hereinafter also abbreviated as “resin composition of the present invention”).
The content of the surface-treated inorganic filler of the present invention in the resin composition is preferably 20% by mass or more, more preferably 30% by mass or more, and more preferably 40% by mass when the nonvolatile component of the resin composition is 100% by mass. The above is more preferable, 50% by mass or more is still more preferable, and 60% by mass or more is particularly preferable. In general, when an insulating layer is formed of a resin composition containing 50% by mass or more of an inorganic filler in an insulating layer of a circuit board, the peel strength of the conductor layer formed on the surface of the insulating layer However, when the insulating layer is formed with a resin composition containing a large amount of the surface-treated inorganic filler of the present invention, the surface of the roughened insulating layer has a surface roughness (Ra). Even if it is small, a high peel strength conductor layer is formed. Even if the surface-treated inorganic filler subjected only to the surface treatment with the silazane compound or the surface-treated inorganic filler subjected only to the surface treatment by the plasma treatment is contained in the resin composition, such an effect is not exhibited. Further, the upper limit of the content of the surface-treated inorganic filler of the present invention in the resin composition is not particularly limited, but when the nonvolatile component of the resin composition is 100% by mass, 85% by mass or less is preferable, and 80% by mass. The following is more preferable, and 75 mass% or less is still more preferable. If it is within such a preferable range, it is advantageous for improving the handleability of the adhesive sheet.

  The resin composition of the present invention is not particularly limited as long as the cured product has sufficient hardness and insulation, and can be used for, for example, an insulating layer of a circuit board (especially an insulating layer of a multilayer printed wiring board). Although not, a composition containing an epoxy resin is preferred. That is, the resin composition of the present invention comprises (A) a surface-treated inorganic filler that has been surface-treated with a silazane compound and then subjected to plasma treatment, (B) an epoxy resin, and (C) a resin composition containing a curing agent. Is preferred.

[(B) Epoxy resin]
The epoxy resin is not particularly limited, but a polyfunctional epoxy resin is preferable. Here, the polyfunctional epoxy resin refers to an epoxy resin having an average number of epoxy groups in one molecule of 2 or more.

  Specifically, for example, bisphenol type epoxy resin (bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, etc.), biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, bixylenol type epoxy resin, naphthol Type epoxy resin, naphthalene type epoxy resin, phosphorus-containing epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, butadiene structure Epoxy resin, bisphenol diglycidyl ether, naphthalenediol diglycidyl ether, phenol glycidyl ether, and alcohol diglycidyl Ether compound, as well as, alkyl-substituted derivatives of these epoxy resins, halides and hydrogenated products or the like. One or more of these epoxy resins can be used.

  Among these, epoxy resins are naphthalene type epoxy resin, bisphenol type epoxy resin, bixylenol type epoxy resin, biphenyl type epoxy resin, naphthol type from the viewpoint of insulation reliability, adhesion to conductor layer, chemical resistance, etc. Epoxy resins are preferable, and naphthalene type epoxy resins, bisphenol type epoxy resins, bixylenol type epoxy resins, and biphenyl type epoxy resins are particularly preferable. The epoxy resin may be liquid or solid, but from the viewpoint of balance of meltability, film formability, physical properties, etc., an embodiment in which the liquid epoxy resin and the solid epoxy resin are used in combination is preferable. . Here, “liquid” and “solid” refer to the state of the epoxy resin at room temperature (25 ° C.).

  The solid epoxy resin is preferably an aromatic epoxy resin from the viewpoint of high glass transition temperature and low coefficient of thermal expansion, more preferably naphthalene type epoxy resin, bixylenol type epoxy resin, biphenyl type epoxy. Resin or the like. One or more solid epoxy resins can be used.

  The liquid epoxy resin is preferably a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolac type epoxy resin, or a naphthalene type epoxy resin. 1 type (s) or 2 or more types can be used for a liquid epoxy resin.

When the liquid epoxy resin and the solid epoxy resin are used in combination, the usage ratio of the liquid epoxy resin and the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is 5-60: 95-40 in terms of mass ratio of nonvolatile content. 10-50: 90-50 are more preferable. If the ratio of the liquid epoxy resin is too small outside this range, the flexibility and melt fluidity of the adhesive sheet tend to decrease when the adhesive sheet is formed from the composition of the present invention. If the ratio is too large, the glass transition temperature of the adhesive sheet tends to decrease and the thermal expansion coefficient tends to increase.

  Preferred specific examples of the epoxy resin include, for example, liquid bisphenol A / F type epoxy resin (“ZX1059” (epoxy equivalent: 165) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), liquid bisphenol A type epoxy. Resin ("jER828EL" (epoxy equivalent: 189) manufactured by Mitsubishi Chemical Corporation), liquid bisphenol F type epoxy resin ("jER806" (epoxy equivalent: 165) manufactured by Mitsubishi Chemical Corporation), phenol novolac type epoxy resin (Mitsubishi) “JER152” (epoxy equivalent: 175) manufactured by Kagaku Co., Ltd., naphthalene type bifunctional epoxy resin (“HP4032SS”, “HP4032D” (epoxy equivalent: 144) manufactured by DIC Corporation), liquid bifunctional epoxy resin (Nippon Steel) “ZX1658” (epoxy equivalent: 135) manufactured by Sumikin Chemical Co., Ltd.) Can be mentioned.

  Also, as the solid epoxy resin, bixylenol type epoxy resin (“YX4000HK” (epoxy equivalent 190) manufactured by Mitsubishi Chemical Corporation), naphthalene type tetrafunctional epoxy resin (“HP4700” manufactured by DIC Corporation (epoxy equivalent: 162)), naphthol type epoxy resin (“ESN-475V” (epoxy equivalent: 332) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), epoxy resin having a butadiene structure (“PB-3600” manufactured by Daicel Chemical Industries, Ltd.), Biphenyl type epoxy resins (“NC3000H”, “NC3000L” (epoxy equivalent: 269) manufactured by Nippon Kayaku Co., Ltd., “YX4000” (epoxy equivalent: 192) manufactured by Mitsubishi Chemical Corporation), and the like are included.

  The content of the epoxy resin in the resin composition is preferably 5% by mass to 40% by mass and more preferably 10% by mass to 30% by mass when the nonvolatile component in the resin composition is 100% by mass. By setting it as this range, the peel strength between the insulating layer and the conductor layer tends to be good.

In the present invention, the epoxy resin preferably has an epoxy equivalent in the range of 50 to 3000, more preferably an epoxy equivalent of 80 to 2000, and still more preferably an epoxy equivalent of 110 to 1000, from the viewpoint of reactivity. . Here, the epoxy equivalent is the mass (g) of the resin containing 1 equivalent of an epoxy group, and is measured according to the method defined in JIS K 7236.

  The weight average molecular weight of an epoxy resin becomes like this. Preferably it is 100-5000, More preferably, it is 250-3000, More preferably, it is 400-2000. The “weight average molecular weight” here is measured by gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the weight average molecular weight by the GPC method is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K-804L / K- manufactured by Showa Denko KK as a column. 804 L can be measured at a column temperature of 40 ° C. using chloroform or the like as a mobile phase, and can be calculated using a standard polystyrene calibration curve.

[(C) Curing agent]
The curing agent is not particularly limited as long as it has a function of curing the epoxy resin. Preferred examples thereof include phenol-based curing agents, naphthol-based curing agents, active ester-based curing agents, benzoxazine-based curing agents, Examples include cyanate ester resins. One or more curing agents can be used.

As a phenol type hardening | curing agent, a phenol novolak type hardening | curing agent is preferable from a heat resistant and water-resistant viewpoint, and a triazine skeleton containing phenol novolak type hardening | curing agent is more preferable. Examples of commercially available products include TD2090 (manufactured by DIC Corporation) as a phenol novolac-based curing agent, and MEH-7700, MEH-7810, and MEH-7851 (Maywa Kasei Co., Ltd.) as biphenyl skeleton-containing phenol novolac-based curing agents. Examples of the triazine skeleton-containing phenol novolak curing agent include LA-1356, LA7052, LA7054, EXB3012, LA3018, EXB3021, HPC-9500 (manufactured by DIC Corporation), and the like.

  As a naphthol type hardening | curing agent, a naphthol novolak type hardening | curing agent is preferable from a heat resistant and water-resistant viewpoint. Examples of commercially available products include SN485, SN495, SN375, SN395, SN170, SN180, SN190 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).

  Examples of the active ester curing agent include EXB-9460, HPC-8000 (manufactured by DIC Corporation), DC808, YLH1030 (manufactured by Mitsubishi Chemical Corporation), and the like. Examples of the benzoxazine-based curing agent include HFB2006M (manufactured by Showa Polymer Co., Ltd.), Pd, Fa (manufactured by Shikoku Kasei Kogyo Co., Ltd.), and the like. Specific examples of the cyanate ester resin include, for example, bisphenol A dicyanate, polyphenol cyanate (oligo (3-methylene-1,5-phenylene cyanate)), 4,4′-methylenebis (2,6-dimethylphenyl cyanate), 4 , 4′-ethylidenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanatephenylmethane), bis (4-cyanate-3,5 A bifunctional cyanate resin such as dimethylphenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, bis (4-cyanatephenyl) ether, Phenol novolac, black Polyfunctional cyanate resin derived from tetrazole novolac, these cyanate resins and partially triazine of prepolymer. Commercially available cyanate ester resins include phenol novolac type polyfunctional cyanate ester resins (“Lonza Japan Co., Ltd.“ PT30 ”, cyanate equivalent 124) and some or all of bisphenol A dicyanate are triazines and trimers The prepolymer ("BA230" manufactured by Lonza Japan Co., Ltd., cyanate equivalent 232), and the like.

  In the resin composition of the present invention, when sufficient curing is performed, the total content of the “epoxy resin” and the “curing agent” is 15 to 15% by mass with respect to 100% by mass of the nonvolatile content in the resin composition. It is preferably 50% by mass. Furthermore, the ratio of the total number of epoxy groups in the epoxy resin and the total number of reactive groups in the curing agent (the total number of epoxy groups: the total number of reactive groups in the curing agent) is determined by combining both of these. It is preferably used in an amount of 1: 0.4 to 2.0, more preferably 1: 0.5 to 1.5. The total number of epoxy groups in the epoxy resin present in the resin composition is a value obtained by dividing the solid mass of each epoxy resin by the epoxy equivalent for all epoxy resins, and the reaction of the curing agent. The total number of groups (active hydroxyl group, active ester group, etc.) is a value obtained by totaling the values obtained by dividing the solid content mass of each curing agent by the reactive group equivalent for all curing agents.

  The content of the curing agent is preferably 1% by mass to 20% by mass and more preferably 3% by mass to 15% by mass when the nonvolatile component in the resin composition is 100% by mass. By setting it as this range, the peel strength between the insulating layer and the conductor layer is easily improved.

[(D) Curing accelerator]
In addition to (C) curing agent, (D) curing accelerator can be further blended in the resin composition of the present invention. Examples of the curing accelerator include organic phosphine compounds, organic phosphonium salt compounds, imidazole compounds, amine adduct compounds, and tertiary amine compounds. Specific examples of organic phosphine compounds and organic phosphonium salt compounds include TPP, TPP-K, TPP-S, TPTP-S, TBP-DA, TPP-SCN, TPTP-SCN (trade name of Hokuko Chemical Co., Ltd.), etc. Is mentioned. Specific examples of the imidazole compound include Curazole 2MZ, 2E4MZ, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2MZ-OK, 2MA-OK, 2PHZ (trade names of Shikoku Kasei Kogyo Co., Ltd.). . Specific examples of the amine adduct compound include Novacure (trade name of Asahi Kasei Kogyo Co., Ltd.) and Fuji Cure (trade name of Fuji Kasei Kogyo Co., Ltd.). Specific examples of the tertiary amine compound include DBU (1,8-diazabiccyclo [5,4,0] undec-7-ene). Two or more curing accelerators may be mixed and used. In the resin composition of the present invention, the content of the curing accelerator is usually 0.1 to 5% by mass relative to 100% by mass of the total amount (nonvolatile content) of the epoxy resin and the curing agent contained in the resin composition. Used in range.

  In addition, when using a cyanate ester resin as a curing agent, an organometallic compound that has been used as a curing catalyst in a system in which an epoxy resin and a cyanate compound are used together can be added for the purpose of shortening the curing time. Good. Examples of organometallic compounds include organic copper compounds such as copper (II) acetylacetonate, organic zinc compounds such as zinc (II) acetylacetonate, and organic such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate. A cobalt compound etc. are mentioned. The addition amount of the organometallic compound is usually in the range of 10 to 500 ppm, preferably 25 to 200 ppm in terms of metal with respect to the cyanate ester resin. Two or more organometallic compounds may be mixed and used. In a system using such a cyanate ester resin and an organometallic compound, the organometallic compound and one or more optional curing accelerators may be used in combination.

[(E) Thermoplastic resin]
(E) thermoplastic resin can be mix | blended with the resin composition of this invention for the objective of providing moderate flexibility to the composition after hardening. Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyimide, polyamideimide, polyethersulfone, polysulfone, and the like. Phenoxy resin and polyvinyl acetal resin are preferable, and phenoxy resin is more preferable. These can use 1 type (s) or 2 or more types. The thermoplastic resin is preferably in the range of 0.5 to 10% by mass and more preferably in the range of 1 to 8% by mass with respect to 100% by mass of the nonvolatile content in the resin composition. If the content is too small, the intended effect of increasing the peel strength of the conductor layer on the insulating layer tends to be insufficient, and if the content is too large, the viscosity of the resin composition becomes too high, Lamination of an adhesive sheet that is difficult to embed when a layer of a resin composition is formed on a conductor pattern (embedding of a composition between adjacent patterns (wirings)) or the like, or that is formed from the resin composition Tend to decrease.

  Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, Examples thereof include those having one or more skeletons selected from a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Examples of commercially available phenoxy resins include 1256 and 4250 (bisphenol A skeleton-containing phenoxy resin) manufactured by Mitsubishi Chemical Corporation, YX8100 (bisphenol S skeleton-containing phenoxy resin) manufactured by Mitsubishi Chemical Corporation, and Mitsubishi Chemical Corporation. YX6954 (bisphenol acetophenone skeleton-containing phenoxy resin), other Nippon Steel & Sumikin Chemical Co., Ltd. FX280, FX293, Mitsubishi Chemical Co., Ltd. YL7553BH30, YL6794, YL7213, YL7290, YL7482 etc. are mentioned.

  The polyvinyl acetal resin is preferably a polyvinyl butyral resin, and specific examples of the polyvinyl acetal resin include those manufactured by Denki Kagaku Kogyo Co., Ltd., Electric Butyral 4000-2, 5000-A, 6000-C, 6000-EP, Sekisui Chemical Co., Ltd. ) Made S-Rec BH series, BX series, KS series, BL series, BM series and the like.

  Specific examples of polyimide include polyimide “Rika Coat SN20” and “Rika Coat PN20” manufactured by Shin Nippon Rika Co., Ltd. Also, a linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (as described in JP 2006-37083 A), a polysiloxane skeleton-containing polyimide (JP 2002-2002). And modified polyimides such as those described in JP-A No. 12667 and JP-A No. 2000-319386.

  Specific examples of the polyamideimide include polyamideimides “Vilomax HR11NN” and “Vilomax HR16NN” manufactured by Toyobo Co., Ltd. In addition, modified polyamideimides such as polysiloxane skeleton-containing polyamideimides “KS9100” and “KS9300” manufactured by Hitachi Chemical Co., Ltd. may be mentioned.

  Specific examples of the polyethersulfone include polyethersulfone “PES5003P” manufactured by Sumitomo Chemical Co., Ltd.

  Specific examples of the polysulfone include polysulfone “P1700” and “P3500” manufactured by Solven Advanced Polymers Co., Ltd.

  The thermoplastic resin preferably has a weight average molecular weight in the range of 8,000 to 150,000, more preferably in the range of 10,000 to 100,000, and particularly preferably in the range of 20,000 to 60,000. When the weight average molecular weight is smaller than the preferred range, the peel strength of the conductor layer on the insulating layer formed of the resin composition of the present invention tends to be reduced. In addition, the roughness of the surface of the insulating layer after the roughening treatment tends to increase.

  The “weight average molecular weight” here is measured by gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the weight average molecular weight by the GPC method is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K-804L / K- manufactured by Showa Denko KK as a column. 804 L can be measured at a column temperature of 40 ° C. using chloroform or the like as a mobile phase, and can be calculated using a standard polystyrene calibration curve.

[(F) Rubber particles]
The resin composition of the present invention may contain (F) rubber particles for the purpose of improving the mechanical strength of the cured product and relaxing the stress. The rubber particles are not dissolved in an organic solvent when preparing the resin composition, are not compatible with components in the resin composition such as an epoxy resin, and exist in a dispersed state in the varnish of the resin composition Is preferred. Such rubber particles can generally be prepared by increasing the molecular weight of the rubber component to a level that does not dissolve in an organic solvent or resin and making it into particles. Specifically, core-shell type rubber particles, Examples thereof include acrylonitrile butadiene rubber particles, crosslinked styrene butadiene rubber particles, and acrylic rubber particles. The core-shell type rubber particles are rubber particles having a core layer and a shell layer. For example, the outer shell layer is a glassy polymer and the inner core layer is a rubbery polymer. Examples include a three-layer structure in which the shell layer is a glassy polymer, the intermediate layer is a rubbery polymer, and the core layer is a glassy polymer. The glass layer is made of, for example, a polymer of methyl methacrylate, and the rubbery polymer layer is made of, for example, a butyl acrylate polymer (butyl rubber). Specific examples of the core-shell type rubber particles include Staphyloid AC3832, AC3816N, (Ganz Kasei Co., Ltd. trade name), and Metabrene KW-4426 (Mitsubishi Rayon Co., Ltd. trade name). Specific examples of acrylonitrile butadiene rubber (NBR) particles include XER-91 (average particle size 0.5 μm, manufactured by JSR Corporation). Specific examples of styrene butadiene rubber (SBR) particles include XSK-500 (average particle size 0.5 μm, manufactured by JSR Corporation). Specific examples of the acrylic rubber particles include methabrene W300A (average particle size 0.1 μm), W450A (average particle size 0.5 μm) (manufactured by Mitsubishi Rayon Co., Ltd.). One or more rubber particles can be used.

The average particle diameter of the rubber particles is preferably in the range of 0.005 to 1 μm, and more preferably in the range of 0.2 to 0.6 μm. The average particle diameter of such rubber particles can be measured using a dynamic light scattering method. For example, rubber particles are uniformly dispersed in a suitable organic solvent by ultrasonic waves, etc., and using FPRA-1000 (manufactured by Otsuka Electronics Co., Ltd.), the particle size distribution of the rubber particles is created on a mass basis, and the median diameter is determined. The average particle diameter is measured.

  When the rubber particles are blended, the content is preferably in the range of 1 to 10% by mass and more preferably in the range of 2 to 5% by mass with respect to 100% by mass of the nonvolatile content in the resin composition. .

[(G) curable resin]
The resin composition of the present invention is (G) curable other than an epoxy resin such as a maleimide compound, a bisallyl nadiimide compound, a vinyl benzyl resin, or a vinyl benzyl ether resin as long as the effects of the present invention are exhibited as necessary. A resin can also be blended. Two or more kinds of such curable resins may be mixed and used. As maleimide resins, BMI1000, BMI2000, BMI3000, BMI4000, BMI5100 (manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI, BMI-70, BMI-80 (manufactured by KEI Kasei Co., Ltd.), ANILIX-MI (Mitsui Chemical Fine) BANI-M, BANI-X (manufactured by Maruzen Petrochemical Co., Ltd.) as a vinyl benzyl resin, V5000 (manufactured by Showa Polymer Co., Ltd.), vinyl benzyl ether resin V1000X, V1100X (manufactured by Showa Polymer Co., Ltd.).

[Flame retardants]
The resin composition of the present invention may contain a flame retardant as long as the effects of the present invention are exhibited. Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide. Examples of organic phosphorus flame retardants include phenanthrene-type phosphorus compounds such as HCA, HCA-HQ, and HCA-NQ manufactured by Sanko Co., Ltd., phosphorus-containing benzoxazine compounds such as HFB-2006M manufactured by Showa Polymer Co., Ltd., and Ajinomoto Co., Inc. Reefos 30, 50, 65, 90, 110, Fine Techno Co., TPP, RPD, BAPP, CPD, TCP, TXP, TBP, TOP, KP140, TIBP, PPQ, Clariant (made by Hokuko Chemical Co., Ltd.) Phosphoric ester compounds such as OP930 manufactured by Daihachi Chemical Co., Ltd., FX289 compounds manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., phosphorus-containing epoxy resins such as FX305, ERF001 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., etc. And phosphorus-containing phenoxy resin. Examples of organic nitrogen-containing phosphorus compounds include phosphate ester amide compounds such as SP670 and SP703 manufactured by Shikoku Kasei Kogyo Co., Ltd., SPB100 and SPE100 manufactured by Otsuka Chemical Co., Ltd., and FP-series manufactured by Fushimi Seisakusho Co., Ltd. Examples thereof include phosphazene compounds. As the metal hydroxide, magnesium hydroxide such as UD65, UD650, UD653 manufactured by Ube Materials Co., Ltd., B-30, B-325, B-315, B-308, B manufactured by Sakai Kogyo Co., Ltd. And aluminum hydroxide such as -303 and UFH-20. One or more flame retardants can be used.

  The resin composition of the present invention may optionally contain various resin additives other than the components described above as long as the effects of the present invention are exhibited. Examples of such resin additives include organic fillers such as silicone powder, nylon powder, and fluorine powder, thickeners such as olben and benton, silicone-based, fluorine-based, and polymer-based antifoaming agents or leveling agents. Adhesion imparting agents such as silane coupling agents, triazole compounds, thiazole compounds, triazine compounds, porphyrin compounds, coloring agents such as phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, carbon black, etc. it can.

[Adhesive sheet]
A resin sheet with a support is obtained by forming a layer of the resin composition of the present invention on a support, and the resin composition of the present invention in a sheet-like substrate (sheet-like fiber substrate) comprising fibers. A prepreg can be obtained by impregnating with. Although the resin composition of the present invention can be applied directly to a circuit board to form an insulating layer, industrially, the resin composition with the support and the prepreg are formed using the resin composition of the present invention. These adhesive sheets are preferably used to form an insulating layer on the circuit board. In the present invention, the “adhesive sheet” is a concept including a resin sheet with a support and a prepreg.

  The resin sheet with the support is prepared by a method known to those skilled in the art, for example, by preparing a resin varnish in which the resin composition is dissolved in an organic solvent, applying the resin varnish on the support, and further heating or blowing hot air. For example, the organic solvent can be dried to form a resin composition layer.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and carbitols such as cellosolve and butyl carbitol. , Aromatic hydrocarbons such as toluene and xylene, amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. One organic solvent may be used, or two or more organic solvents may be used in combination.

  The drying conditions are not particularly limited, but the drying is performed so that the content ratio of the organic solvent in the resin composition layer is usually 10% by mass or less, preferably 5% by mass or less. As drying conditions, suitable drying conditions can be appropriately set by simple experiments. Depending on the amount of organic solvent in the varnish, for example, a varnish containing 30 to 60% by mass of an organic solvent can be dried at 50 to 150 ° C. for about 3 to 10 minutes.

  The thickness of the resin composition layer formed in the resin sheet with a support is generally not less than the thickness of the conductor layer that the circuit board has. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 5 to 300 μm, more preferably 10 to 200 μm, and more preferably 10 to 100 μm. Further preferred. The resin composition layer may be protected by a protective film described later. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches.

  Examples of the support include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyesters such as polyethylene naphthalate, plastic films such as polycarbonate and polyimide. As the plastic film, PET is particularly preferable. Moreover, metal foils, such as copper foil and aluminum foil, can also be used as a support body. The protective film is preferably a plastic film similar to the support. Although the thickness of a support body is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers. The thickness of the protective film is not particularly limited, but is usually 1 to 40 μm, preferably 10 to 30 μm. Further, the support and the protective film may be subjected to a release treatment in addition to the mat treatment and the corona treatment. Examples of the release treatment include a release treatment with a release agent such as a silicone resin release agent, an alkyd resin release agent, and a fluororesin release agent. The support-attached resin sheet preferably has a layer structure of protective film / resin composition layer / support. In the resin sheet with a support, the resin composition layer formed on the support is preferably formed such that the area of the layer is smaller than the area of the support. The resin sheet with a support can be rolled up, stored and stored.

  As the sheet-like fiber base material in the prepreg, for example, those commonly used as a fiber base material for prepreg made of glass cloth, aramid fiber, etc. can be used. It can be obtained by impregnation by a melt method or a solvent method and semi-curing by heating. In the hot melt method, without dissolving the resin in an organic solvent, the resin is once coated on the resin and a coated paper having good releasability, and then laminated on a sheet-like fiber substrate, or directly applied by a die coater. Thus, a prepreg is manufactured. The solvent method is a method in which a sheet-like fiber base material is immersed in a resin varnish obtained by dissolving a resin in an organic solvent, the sheet-like fiber base material is impregnated with the resin varnish, and then dried. Moreover, the prepreg with a support body can be prepared by heating and laminating the resin sheet with a support body from both sides of the sheet-like fiber base material continuously under heat and pressure. In this case, although a support body is provided on both surfaces of the prepreg, either one of the support bodies corresponds to a protective film. In addition, the specific constituent materials and thicknesses of the support and the protective film in the prepreg with the support follow those in the support and the protective film of the above-described resin sheet with the support.

  In the case of a prepreg with a support, it can be rolled up, stored and stored. In this case, the prepreg with a support preferably has a layer structure of protective film / prepreg / support.

  A circuit board such as a multilayer printed wiring board using the adhesive sheet of the present invention can be produced, for example, as follows. When the adhesive sheet is a resin sheet with a support, when the resin composition layer is protected by a protective film, after peeling these, the resin composition layer is directly in contact with the inner circuit board so that the resin composition layer is in direct contact with the inner circuit board. Laminate on one or both sides. In laminating such an adhesive sheet, a method of laminating the inner layer circuit board under reduced pressure by a vacuum laminating method is suitably used. The laminating method may be a batch method or a continuous method using a roll. Further, the adhesive sheet and the inner layer circuit board may be heated (preheated) as necessary before lamination.

  The “inner circuit board” as used in the present invention is mainly a conductor layer patterned on one or both sides of a substrate such as a glass epoxy, metal substrate, polyester substrate, polyimide substrate, BT resin substrate, thermosetting polyphenylene ether substrate, etc. (Circuit) is formed. In addition, when manufacturing a multilayer printed wiring board in which conductor layers and insulating layers are alternately formed, and one or both surfaces are patterned conductor layers (circuits), an insulating layer and a conductor layer are further formed. The intermediate product to be included is also included in the inner layer circuit board in the present invention. In the inner layer circuit board, the surface of the conductor circuit layer is preferably roughened by a blackening process or the like from the viewpoint of adhesion of the insulating layer to the inner layer circuit board.

The laminating conditions are preferably a pressure bonding temperature (laminating temperature) of 70 to 140 ° C. and a pressure bonding pressure of preferably 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ). Lamination is preferably performed under a reduced pressure of 20 mmHg (26.7 hPa) or less.

  The vacuum lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum applicator manufactured by Nichigo Morton, a vacuum pressurizing laminator manufactured by Meiki Seisakusho, a roll dry coater manufactured by Hitachi Industries, Ltd., and Hitachi AIC. A vacuum laminator manufactured by Co., Ltd. can be exemplified.

After laminating the adhesive sheet on the inner layer circuit board, when the support is peeled off, it can be peeled off and thermally cured to form an insulating layer on the inner layer circuit board. The conditions of heat curing are selected in the range of 20 to 180 minutes at 150 to 220 ° C, more preferably 30 to 120 minutes at 160 to 200 ° C. In addition, when a support body is not peeled before hardening, it peels after formation of an insulating layer. If the support is peeled off after the resin composition layer is heat-cured, adhesion of dust and the like in the curing step can be prevented, and the surface smoothness of the insulating layer after curing can be improved. In the case of peeling after curing, the support is usually subjected to a release treatment in advance.

  Next, holes are formed in the insulating layer formed on the inner circuit board to form via holes and through holes. Drilling can be performed by a known method such as drilling, laser, or plasma, or a combination of these methods if necessary. However, drilling by a laser such as a carbon dioxide laser or YAG laser is the most common method. .

  Next, a roughening process is performed on the surface of the insulating layer. The roughening treatment in the present invention is usually preferably carried out by a wet roughening method using an oxidizing agent. Examples of the oxidizing agent include permanganate (potassium permanganate, sodium permanganate, etc.), dichromate, ozone, hydrogen peroxide / sulfuric acid, nitric acid and the like. Preferably, an alkaline permanganate solution (eg, potassium permanganate, sodium hydroxide solution of sodium permanganate), which is an oxidizer widely used for roughening an insulating layer in the production of multilayer printed wiring boards by a built-up method. It is preferable to perform roughening using.

The roughness of the roughened surface obtained by roughening the surface of the insulating layer is preferably 400 nm or less, more preferably 350 nm or less, and even more preferably 300 nm or less in terms of Ra value when forming fine wiring. Moreover, 50 nm or more is preferable from the point of obtaining fixed peel strength, and 100 nm or more is more preferable. Here, the Ra value is a kind of numerical value representing the surface roughness, and is called arithmetic average roughness. Specifically, the absolute value of the height changing in the measurement region is expressed by the average line. Measured from a certain surface and arithmetically averaged. For example, using WYKO NT3300 manufactured by Becoin Instruments Co., Ltd., it can be obtained from a numerical value obtained with a measurement range of 121 μm × 92 μm using a VSI contact mode and a 50 × lens.

  Next, a conductor layer is formed on the roughened insulating layer surface by a method combining electroless plating and electrolytic plating. Alternatively, a plating resist having a pattern opposite to that of the conductor layer can be formed, and the conductor layer can be formed only by electroless plating. In addition, after forming the conductor layer, the peel strength of the conductor layer can be further improved and stabilized by annealing at 150 to 200 ° C. for 20 to 90 minutes. The thickness of the conductor layer thus formed is not particularly limited, but is generally about 5 to 70 μm, preferably about 10 to 50 μm. The peel strength of the conductor layer is preferably 0.3 kgf / cm or more, and more preferably 0.35 kgf / cm or more. The upper limit is not limited, but is generally 10 kgf / cm or less.

  In addition, as a method of patterning the conductor layer to form a circuit, for example, a subtractive method or a semi-additive method known to those skilled in the art can be used.

When the adhesive sheet is a prepreg, a circuit board such as a multilayer printed wiring board can be produced as follows, for example. One or several prepregs of the present invention are stacked on the inner layer circuit board, and a metal plate is sandwiched through a release film, and press laminated under pressure and heating conditions. The pressure is preferably 5 to 40 kgf / cm ² (49 × 10 ^{4 to} 392 × 10 ⁴ N / m ² ), and the temperature is preferably 120 to 200 ° C. for 20 to 100 minutes. Moreover, it can also be manufactured by laminating on an inner layer circuit board by a vacuum laminating method and then heat-curing. Thereafter, in the same manner as described above, the surface of the prepreg cured with an oxidizing agent is roughened, and then the conductor layer is formed by plating, whereby a circuit board such as a multilayer printed wiring board can be manufactured.

EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example and a comparative example, these do not restrict | limit this invention in any meaning. In the following description, “part” means “part by mass”.
<Example 1>
(Surface treatment of inorganic filler)
300 parts of surface-treated spherical silica (“SC2500-SQ” manufactured by Admatechs Co., Ltd., average particle size 0.5 μm, carbon content: 0.025 mg / m ² ) surface-treated with hexamethyldisilazane was rotated. Using a vacuum plasma apparatus (“YHS-DΦS” manufactured by Sakai Semiconductor Co., Ltd.), plasma irradiation was performed for 60 seconds under conditions of 40 Pa, 100 W and a temperature of 25 ° C. in an Ar atmosphere. did. The average particle size of the inorganic filler A was 0.5 μm.

(Production of resin varnish, production of adhesive sheet)
5 parts by mass of naphthalene type epoxy resin (epoxy equivalent 144, “HP4032SS” manufactured by DIC Corporation), 20 parts by mass of liquid bisphenol type epoxy resin (epoxy equivalent 165, “ZX1059” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), xylenol type 10 parts by mass of epoxy resin (epoxy equivalent 190, “YX4000HK” manufactured by Mitsubishi Chemical Corporation) and 10 parts by mass of biphenyl type epoxy resin (epoxy equivalent of about 269, “NC3000H” manufactured by Nippon Kayaku Co., Ltd.) The mixture was dissolved by heating with stirring in parts by mass. After cooling to room temperature, there are 5 parts of rubber particles (manufactured by Aika Kogyo Co., Ltd., Staphyloid AC3816N), a flame retardant (“HCA-HQ” produced by Sanko Co., Ltd.), 10- (2,5-dihydroxyphenyl). ) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 2 μm) 2 parts by mass and 120 parts by mass of inorganic filler A are mixed and dispersed uniformly using a high-pressure disperser. To obtain a resin mixture.

  6 parts by mass of a triazine skeleton-containing phenol novolac curing agent (“LA-1356” manufactured by DIC Corporation, hydroxyl group equivalent 146), naphthol aralkyl type phenol curing agent (Nippon Steel & Sumikin Chemical Co., Ltd.) with respect to the obtained resin mixture "SN485" manufactured, 6 parts by mass of hydroxyl group equivalent 215), 3 parts by mass of phenoxy resin ("YL7553" manufactured by Mitsubishi Chemical Corporation, weight average molecular weight 35000), 0.07 parts by mass of curing accelerator (4-dimethylaminopyridine) Then, 15 parts by mass of methyl ethyl ketone (MEK) and 15 parts by mass of cyclohexanone were mixed and dispersed uniformly with a high-speed rotary mixer to prepare a resin varnish.

  Next, it was coated on a polyethylene terephthalate (thickness 38 μm, hereinafter abbreviated as “PET”) with a die coater so that the thickness of the resin composition after drying was 40 μm, and 70 to 100 ° C. (average 90 ° C.). ) For 5 minutes (residual solvent amount of about 2% by mass). Subsequently, it wound up in roll shape, bonding a 15-micrometer-thick polypropylene film on the surface of the resin composition layer obtained by drying. The obtained roll-shaped adhesive sheet was slit into a width of 507 mm, and an adhesive sheet having a size of 507 mm × 336 mm was obtained therefrom.

<Comparative Example 1>
(Surface treatment of inorganic filler)
Non-surface-treated spherical silica (“SO-C2” manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) was used as the inorganic filler C.

(Production of resin varnish, production of adhesive sheet)
In Example 1, an adhesive sheet was obtained in exactly the same manner as in Example 1 except that the inorganic filler C was used instead of the inorganic filler A.

<Comparative Example 2>
(Surface treatment of inorganic filler)
Non-surface-treated spherical silica (“SO-C2” manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) was subjected to plasma treatment under the same conditions as in Example 1 and the surface-treated spherical silica was used as the inorganic filler. D.

(Production of resin varnish, production of adhesive sheet)
In Example 1, an adhesive sheet was obtained in exactly the same manner as in Example 1 except that the inorganic filler D was used instead of the inorganic filler A.

<Comparative Example 3>
(Surface treatment of inorganic filler)
Surface-treated spherical silica (“SC2500-SQ” manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) surface-treated with hexamethyldisilazane was used as the inorganic filler E.

(Production of resin varnish, production of adhesive sheet)
In Example 1, an adhesive sheet was obtained in exactly the same manner as in Example 1 except that the inorganic filler E was used instead of the inorganic filler A.

<Example 2>
(Surface treatment of inorganic filler)
Except for using surface-treated spherical silica surface-treated with hexamethyldisilazane (“SC1500-SQ” manufactured by Admatechs Co., Ltd., average particle size 0.2 μm, carbon amount: 0.04 mg / m ² ). In the same manner as in Example 1, an inorganic filler B was obtained. The average particle diameter of the inorganic filler B was 0.2 μm.

(Production of resin varnish, production of adhesive sheet)
In Example 1, an adhesive sheet was obtained in exactly the same manner as in Example 1 except that the inorganic filler B was used instead of the inorganic filler A.

<Comparative example 4>
(Surface treatment of inorganic filler)
Non-surface-treated spherical silica (“SO-C1” manufactured by Admatechs Co., Ltd., average particle size 0.2 μm) was used as the inorganic filler F.

(Production of resin varnish, production of adhesive sheet)
In Example 1, an adhesive sheet was obtained in exactly the same manner as in Example 1 except that the inorganic filler F was used instead of the inorganic filler A.

<Comparative Example 5>
(Surface treatment of inorganic filler)
Non-surface-treated spherical silica (“SO-C1” manufactured by Admatechs Co., Ltd., average particle diameter 0.2 μm) was subjected to plasma treatment under the same conditions as in Example 1 and inorganic filler was used as the surface-treated spherical silica. G.

(Production of resin varnish, production of adhesive sheet)
In Example 1, an adhesive sheet was obtained in exactly the same manner as in Example 1 except that the inorganic filler G was used instead of the inorganic filler A.

<Comparative Example 6>
(Surface treatment of inorganic filler)
Surface-treated spherical silica treated with hexamethyldisilazane (“SC1500-SQ” manufactured by Admatechs Co., Ltd., average particle size 0.2 μm) was used as the inorganic filler H.

(Production of resin varnish, production of adhesive sheet)
In Example 1, an adhesive sheet was obtained in exactly the same manner as in Example 1 except that the inorganic filler H was used instead of the inorganic filler A.

Next, measurement methods and evaluation results are shown.
(Hardened body formation, roughening, plating)
(1) Inner layer circuit board surface treatment
A glass cloth base epoxy resin double-sided copper-clad laminate (with a copper foil thickness of 18 μm, a substrate thickness of 0.3 mm, “R5715ES” manufactured by Matsushita Electric Works Co., Ltd.) on which an inner layer circuit is formed is attached to CZ8100 manufactured by MEC Co., Ltd. The copper surface was roughened by dipping in an azole copper complex and a surface treatment agent containing an organic acid.
(2) Lamination process of adhesive sheet
The adhesive sheet is a batch type vacuum pressure laminator (manufactured by Meiki Seisakusho, "MVLP-5
00 ”) was laminated on both sides of the inner circuit board so that the adhesive sheet was bonded to the inner circuit board. The laminating process was performed by reducing the pressure for 30 seconds to reduce the air pressure to 13 hPa or less, and then pressing at 100 ° C. and a pressure of 0.74 MPa for 30 seconds.
(3) Curing of resin composition
The PET film was peeled off from the laminated adhesive sheet, and a cured body was formed under curing conditions of 100 ° C. for 30 minutes and further 180 ° C. for 30 minutes.
(4) Production of Roughened Cured Body The cured body is immersed in a swelling liquid (Atotech Japan Co., Ltd., “Swelling Dip / Seculigand P”, containing diethylene glycol monobutyl ether) at 60 ° C. for 5 minutes, and then the roughened liquid. (Atotech Japan Co., Ltd., “Concentrate Compact P”, an aqueous solution having a potassium permanganate concentration of about 6 mass% and a sodium hydroxide concentration of about 4 mass%) was immersed at 80 ° C. for 20 minutes. Finally, it was immersed for 5 minutes at 40 ° C. in a neutralizing solution (“Reduction Solutionin Securigant P” manufactured by Atotech Japan Co., Ltd.) to obtain a roughened cured body.
(5) Manufacture of laminated body An inner layer circuit board having a roughened cured body on both sides is immersed in an electroless plating solution containing palladium chloride (PdCl ₂ ), and then immersed in an electroless copper plating solution for roughening and curing. A plating seed layer was formed on the body surface. Then, after annealing for 30 minutes at 150 ° C., an etching resist was formed on the plating seed layer, and the plating seed layer was patterned by etching. Subsequently, copper sulfate electrolytic plating was performed to form a copper layer (conductor layer) having a thickness of 30 μm, and then annealed at 180 ° C. for 60 minutes to obtain a laminate on both surfaces of the inner layer circuit board.

(Peeling strength of the plating conductor layer (peel strength))
When the conductor layer of the laminate is cut into a 10 mm wide and 100 mm long part, this end is peeled off and gripped with a gripper, and 35 mm is pulled off in the vertical direction at a speed of 50 mm / min at room temperature. The load of was measured.

(Arithmetic average roughness (Ra value) after roughening
Using a non-contact type surface roughness meter (BYCO Instruments WYKO NT3300), the Ra value was determined by a numerical value obtained by setting the measurement range to 121 μm × 92 μm with a VSI contact mode and a 50 × lens. The Ra value of the manufactured roughened cured product was measured at 10 locations, and the average value of the 10 Ra values was calculated.

  The following Tables 1 and 2 show the compounding ratios of the respective components of the resin compositions of Examples and Comparative Examples and the results of evaluation tests.

Claims (15)

  Surface-treated inorganic filler that has been subjected to plasma treatment after surface treatment with a silazane compound.   The surface-treated inorganic filler according to claim 1, wherein the plasma treatment is a treatment in which argon plasma is irradiated for 30 seconds or more under a condition of 100 W or more. The silazane compound is hexamethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, octamethyltrisilazane, hexa (t-butyl) disilazane, hexabutyldisilazane, hexaoctyldisilazane. 1,3-diethyltetramethyldisilazane, 1,3-di-n-octyltetramethyldisilazane, 1,3-diphenyltetramethyldisilazane, 1,3-dimethyltetraphenyldisilazane, 1,3-diethyl Tetramethyldisilazane, 1,1,3,3-tetraphenyl-1,3-dimethyldisilazane, 1,3-dipropyltetramethyldisilazane, hexamethylcyclotrisilazane, hexaphenyldisilazane, dimethylaminotrimethylsilazane , Trisilazane, cyclotrisilazane, and 1,1,3,3 The surface-treated inorganic filler according to claim 1 or 2, which is one or more selected from the group consisting of 1,5,5-hexamethylcyclotrisilazane.   The surface-treated inorganic filler according to any one of claims 1 to 3, wherein the average particle diameter is 0.01 to 5 µm.   The surface-treated inorganic filler according to any one of claims 1 to 4, wherein the inorganic filler is silica.   The surface-treated inorganic filler according to any one of claims 1 to 5, wherein the inorganic filler is a spherical particle.   The surface treatment inorganic filler of any one of Claims 1-6 used for the resin composition for insulating layer formation of a circuit board.   A method for producing a surface-treated inorganic filler, comprising subjecting an inorganic filler to a surface treatment with a silazane compound and further subjecting the inorganic filler to a plasma treatment.   (A) A resin composition comprising the surface-treated inorganic filler according to any one of claims 1 to 7, (B) an epoxy resin, and (C) a curing agent.   The resin composition according to claim 9, wherein the content of the surface-treated inorganic filler is 50% by mass or more when the nonvolatile component in the resin composition is 100% by mass.   The resin composition according to claim 9 or 10, further comprising (D) a curing accelerator.   Furthermore, (E) The resin composition of any one of Claims 9-11 containing a thermoplastic resin.   The adhesive sheet in which the layer of the resin composition of any one of Claims 9-12 is formed on a support body.   A prepreg formed by impregnating the resin composition according to any one of claims 9 to 12 in a sheet-like fiber base material.   The circuit board containing the insulating layer formed with the hardened | cured material of the resin composition of any one of Claims 9-12.