JP2022159323A - Cured body, b-stage film, and multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cured body which can suppress warpage of an insulating layer, and can suppress cracking or fracture of an insulating layer in the periphery of a via hole.

SOLUTION: A cured body is a cured body of a resin material, and is a cured body used as an insulating material. When the component contained in the cured body is separated into three components such as a hard component at 170°C, a middle component at 170°C, and a soft component at 170°C, in increasing order of spin-spin relaxation time, based on a free induction decay curve at 170°C obtained using a pulse NMR, a content of the soft component at 170°C is 5% or more and 40% or less in 100% of the total of the contents of the hard component at 170°C, the middle component at 170°C and the soft component 170°C.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a cured resin material and a B-stage film. The present invention also relates to a multilayer printed wiring board using the cured product.

2. Description of the Related Art Conventionally, various resin materials have been used to obtain electronic components such as semiconductor devices, laminates and printed wiring boards. For example, in a multilayer printed wiring board, a resin material is used to form an insulating layer for insulation between internal layers and to form an insulating layer positioned on a surface layer. Wiring, which is generally made of metal, is laminated on the surface of the insulating layer. Moreover, in order to form the insulating layer, a resin film obtained by forming the resin material into a film may be used. The above resin materials and resin films are used as insulating materials for multilayer printed wiring boards including build-up films.

Patent Document 1 below discloses a resin composition containing a compound having a maleimide group, a divalent group having at least two imide bonds, and a saturated or unsaturated divalent hydrocarbon group. . Patent Literature 1 describes that a cured product of this resin composition can be used as an insulating layer of a multilayer printed wiring board or the like.

Patent Document 2 below describes (A) an epoxy resin, (B) an active ester compound, (C) a carbodiimide compound, (D) a thermoplastic resin and (E) an inorganic filler, and the content of the (E) component However, when the non-volatile component in the resin composition is taken as 100% by mass, a resin composition is disclosed in which the content is 40% by mass or more.

WO2016/114286A1 JP 2016-027097 A

When manufacturing a multilayer printed wiring board, an insulating layer is formed by heating and curing a resin material. Also, via holes are formed during the manufacture of multilayer printed wiring boards.

In addition, with conventional resin materials such as those described in Patent Documents 1 and 2, the flexibility of the insulating layer is small, and when the insulating layer is exposed to high temperatures, the insulating layer warps, and the insulating layer may be deformed around the via hole. Cracks or splits are likely to occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cured resin material and a B-stage film that can suppress warping of an insulating layer and cracks or cracks in the insulating layer around a via hole. Moreover, this invention is providing the multilayer printed wiring board using the said hardening body.

According to a broad aspect of the present invention, a cured body of a resin material is used as an insulating material, and based on a free induction decay curve at 170° C. obtained using pulse NMR, the cured body is separated into three components, a hard component at 170 ° C., a middle component at 170 ° C., and a soft component at 170 ° C., in order of shortest spin-spin relaxation time, the hard component at 170 ° C. The content of the soft component at 170°C is 5% or more and 40% or less in the total 100% of the content of the component, the content of the middle component at 170°C, and the content of the soft component at 170°C. A cured body is provided.

In a specific aspect of the cured body according to the present invention, the total of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C is 100%. In particular, the content of the soft component at 170° C. is 10% or more and 25% or less.

In a specific aspect of the cured body according to the present invention, based on the free induction decay curve at 30 ° C. obtained using pulse NMR, the components contained in the cured body are sorted in descending order of spin-spin relaxation time, When separated into three components, a hard component at 30°C, a middle component at 30°C, and a soft component at 30°C, the content of the hard component at 170°C and the content of the middle component at 170°C and the content of the soft component at 170°C, the content of the soft component at 170°C, the content of the hard component at 30°C, and the content of the middle component at 30°C The ratio of the content of the soft component at 30° C. to the content of the soft component at 30° C. in the total 100% of the amount and the content of the soft component at 30° C. is 2 or more and 30 or less.

In a specific aspect of the cured body according to the present invention, the resin material contains a thermosetting compound and an inorganic filler.

In a specific aspect of the cured body according to the present invention, the resin material comprises a thermosetting compound and a curing agent, the thermosetting compound comprises an epoxy compound, and the curing agent comprises an active ester compound. including.

According to a broad aspect of the invention, a B-staged film used as an insulating material, the B-staged film being heated at 130° C. for 30 minutes, 170° C. for 30 minutes, 200° C. for 1 hour, By heating in this order, a cured body of a B-stage film was obtained, and based on the free induction decay curve at 170 ° C. obtained using pulse NMR, the components contained in the cured body were identified as having a short spin-spin relaxation time. When separated in order into three components, a hard component at 170°C, a middle component at 170°C, and a soft component at 170°C, the content of the hard component at 170°C and the content of the middle component at 170°C. A B-stage film is provided in which the content of the soft component at 170°C is 5% or more and 40% or less in the total 100% of the content and the content of the soft component at 170°C.

In a specific aspect of the B-stage film according to the present invention, the total of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C is 100. %, the content of the soft component at 170° C. is 10% or more and 25% or less.

In a specific aspect of the B-stage film according to the present invention, the components contained in the cured body are sorted in descending order of spin-spin relaxation time based on the free induction decay curve at 30° C. obtained using pulse NMR. , the hard component at 30°C, the middle component at 30°C, and the soft component at 30°C, the content of the hard component at 170°C and the content of the middle component at 170°C of the content of the soft component at 170°C, the content of the hard component at 30°C and the content of the middle component at 30°C in the total 100% of the amount and the content of the soft component at 170°C The ratio of the content of the soft component at 30° C. to the content of the soft component at 30° C. in the total 100% of the content and the content of the soft component at 30° C. is 2 or more and 30 or less.

The B-stage film according to the present invention is suitably used for forming insulating layers in multilayer printed wiring boards.

According to a broad aspect of the present invention, the present invention comprises a circuit board, a plurality of insulating layers disposed on a surface of the circuit board, and a metal layer disposed between the plurality of insulating layers, wherein A multilayer printed wiring board is provided in which the material of at least one of the insulating layers is the above-described cured material.

A cured body according to the present invention is a cured body of a resin material, and is a cured body used as an insulating material. In the present invention, based on the free induction decay curve at 170 ° C. obtained using pulse NMR, the components contained in the cured body are sorted in order of shortest spin-spin relaxation time at 170 ° C., hard components at 170 ° C. It separates into three components, a middle component at 170°C and a soft component at 170°C. In the cured body according to the present invention, the above 170°C The content of the soft component in is 5% or more and 40% or less. Since the cured body according to the present invention has the above configuration, warping of the insulating layer can be suppressed, and cracking or splitting of the insulating layer around the via hole can be suppressed.

The B-stage film according to the present invention is a B-stage film used as an insulating material. In the present invention, the B-stage film is heated at 130° C. for 30 minutes, 170° C. for 30 minutes and 200° C. for 1 hour in this order to obtain a cured B-stage film. In the present invention, based on the free induction decay curve at 170 ° C. obtained using pulse NMR, the components contained in the cured body are sorted in order of shortest spin-spin relaxation time at 170 ° C., hard components at 170 ° C. It separates into three components, a middle component at 170°C and a soft component at 170°C. In the B stage film according to the present invention, the content of the hard component at 170° C., the content of the middle component at 170° C., and the content of the soft component at 170° C. out of the total 100%, the above 170 The content of the soft component at °C is 5% or more and 40% or less. Since the B-stage film according to the present invention has the above structure, it is possible to suppress the warping of the insulating layer and the cracking or breakage of the insulating layer around the via hole.

FIG. 1 is a cross-sectional view schematically showing a multilayer printed wiring board using a cured product according to one embodiment of the present invention.

The present invention will be described in detail below.

A cured body according to the present invention is a cured body of a resin material, and is a cured body used as an insulating material.

In the present invention, based on the free induction decay curve at 170 ° C. obtained using pulse NMR, the components contained in the cured body are sorted in order of shortest spin-spin relaxation time at 170 ° C., hard components at 170 ° C. It separates into three components, a middle component at 170°C and a soft component at 170°C. In the cured body according to the present invention, the above 170°C The content of the soft component in is 5% or more and 40% or less.

The B-stage film according to the present invention is a B-stage film used as an insulating material.

In the present invention, the B-stage film is heated at 130° C. for 30 minutes, 170° C. for 30 minutes and 200° C. for 1 hour in this order to obtain a cured B-stage film. In the present invention, based on the free induction decay curve at 170 ° C. obtained using pulse NMR, the components contained in the cured body are sorted in order of shortest spin-spin relaxation time at 170 ° C., hard components at 170 ° C. It separates into three components, a middle component at 170°C and a soft component at 170°C. In the B stage film according to the present invention, the content of the hard component at 170° C., the content of the middle component at 170° C., and the content of the soft component at 170° C. out of the total 100%, the above 170 The content of the soft component at °C is 5% or more and 40% or less.

Since the cured product and the B-stage film according to the present invention have the above configuration, warping of the insulating layer can be suppressed, and cracking or splitting of the insulating layer around the via hole can be suppressed. In the cured product and B-stage film according to the present invention, the warpage of the insulating layer can be suppressed, the stress relaxation of the insulating layer can be moderated, and the linear expansion coefficient can be reduced. It is possible to suppress cracks or cracks in the insulating layer of Therefore, in the cured body and B stage film according to the present invention, the connection reliability can be improved in the thermal cycle test.

In the cured product and B-stage film according to the present invention, the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C are all 100% of the total. , the content of the soft component at 170° C. is 5% or more and 40% or less. In the present invention, the content of the soft component at 170°C is relatively large. Therefore, stress relaxation and flexibility of the cured body in a high-temperature region can be improved, and warping of the insulating layer and cracking or splitting of the insulating layer around the via hole can be prevented. The sum of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C is the total content of the components of the cured product at 170°C. quantity.

In the cured product and B-stage film according to the present invention, the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C are all 100% of the total. , the content of the soft component at 170°C is preferably 7.5% or more, more preferably 10% or more, and still more preferably 12% or more. In the cured product and B-stage film according to the present invention, the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C are all 100% of the total. , the content of the soft component at 170°C is preferably 25% or less, more preferably 20% or less. When the content of the soft component at 170° C. is equal to or higher than the lower limit and equal to or lower than the upper limit, it is possible to more effectively prevent warping of the insulating layer and cracking or breakage of the insulating layer around the via hole.

In the present invention, based on the free induction decay curve at 30 ° C. obtained using pulse NMR, the components contained in the above-mentioned cured body are sorted in order of shortest spin-spin relaxation time at 30 ° C., hard components at 30 ° C., 30 ° C. It is preferable to separate into three components, a middle component at 30°C and a soft component at 30°C.

In the cured product and B stage film according to the present invention, the content of the hard component at 30 ° C., the content of the middle component at 30 ° C., and the content of the soft component at 30 ° C. are included in the total 100% , the content of the soft component at 30°C is preferably 0.1% or more, more preferably 0.5% or more. In the cured product and B stage film according to the present invention, the content of the hard component at 30 ° C., the content of the middle component at 30 ° C., and the content of the soft component at 30 ° C. are included in the total 100% , the content of the soft component at 30°C is preferably 10% or less, more preferably 5% or less, still more preferably 3% or less. When the content of the soft component at 30°C is equal to or higher than the above lower limit, the effect of the present invention can be exhibited more effectively. The sum of the content of the hard component at 30°C, the content of the middle component at 30°C, and the content of the soft component at 30°C is the total content of the components of the cured product at 30°C. quantity.

The content of the soft component at 170°C in the total 100% of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C Content (1). The content of the soft component at 30°C in the total 100% of the content of the hard component at 30°C, the content of the middle component at 30°C, and the content of the soft component at 30°C Content (2). In the cured product and B-stage film according to the present invention, the ratio of content (1) to content (2) (content (1)/content (2)) is preferably 2 or more, more preferably 5 or more , preferably 30 or less, more preferably 20 or less, still more preferably 15 or less. When the ratio (content (1)/content (2)) is not less than the lower limit and not more than the upper limit, the effects of the present invention can be exhibited more effectively.

In the cured product and B stage film according to the present invention, the spin-spin relaxation time of the soft component at 170° C. is preferably 0.15 milliseconds or more, more preferably 0.25 milliseconds or more, and preferably 0.25 milliseconds or more. It is 6 milliseconds or less, more preferably 0.5 milliseconds or less. When the spin-spin relaxation time of the soft component at 170° C. is not less than the lower limit and not more than the upper limit, the effects of the present invention can be exhibited more effectively.

In the cured product and B-stage film according to the present invention, the spin-spin relaxation time of the soft component at 30° C. is preferably 0.1 milliseconds or more, more preferably 0.2 milliseconds or more, and preferably 0.2 milliseconds or more. It is 5 milliseconds or less, more preferably 0.4 milliseconds or less. When the spin-spin relaxation time of the soft component at 30° C. is not less than the lower limit and not more than the upper limit, the effects of the present invention can be exhibited more effectively.

In the cured product and B-stage film according to the present invention, the ratio of the spin-spin relaxation time of the soft component at 170 ° C. to the spin-spin relaxation time of the soft component at 30 ° C. (the ratio of the spin-spin relaxation time of the soft component at 170 ° C. The spin-spin relaxation time/spin-spin relaxation time of the soft component at 30° C.) is preferably 2 or less. If the above ratio (spin-spin relaxation time of the soft component at 170° C./spin-spin relaxation time of the soft component at 30° C.) is equal to or less than the above upper limit, cracks or splits in the insulating layer around the via hole are less likely to occur. can be suppressed more effectively.

The content of the hard component, the middle component and the soft component at 30°C, the content of the hard component, the middle component and the soft component at 170°C, the spin-spin relaxation time of the soft component at 170°C and the above Specifically, the spin-spin relaxation time of the soft component at 30° C. can be determined by the method described in Examples.

The content of the soft component at 170°C and the soft component at 30°C, the ratio (content (1)/content (2)), the soft component at 170°C and the soft component at 30°C As a method for controlling the spin-spin relaxation time in the above preferred range, the following method can be mentioned. (1) By controlling the heating temperature during pre-curing, the phase separation can be alleviated and the content of the soft component at 170° C. can be increased. (2) The temperature dependence of the soft component can be controlled by setting the Tg of the polymer component to 100°C or higher and 150°C or lower.

Hereinafter, the details of each component used in the cured product of the present invention, the resin material for obtaining the cured product, and the use of the cured product of the present invention will be described. Details of each component used in the B-stage film according to the present invention and applications of the B-stage film according to the present invention will be described below. In addition, the B stage film is a resin material.

[Thermosetting compound]
The resin material preferably contains a thermosetting compound. The cured body is preferably a thermoset of the resin material. Examples of the thermosetting compounds include epoxy compounds, maleimide compounds, styrene compounds, phenoxy compounds, oxetane compounds, episulfide compounds, (meth)acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, and silicone compounds. is mentioned. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

From the viewpoint of further enhancing the thermal dimensional stability of the cured product, the thermosetting compound preferably contains the epoxy compound or the maleimide compound, and more preferably contains the epoxy compound.

<Epoxy compound>
A conventionally well-known epoxy compound can be used as the epoxy compound. Only one type of the epoxy compound may be used, or two or more types may be used in combination.

Examples of the epoxy compounds include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenol novolac type epoxy compounds, biphenyl type epoxy compounds, biphenyl novolac type epoxy compounds, biphenol type epoxy compounds, and naphthalene type epoxy compounds. , fluorene type epoxy compound, phenol aralkyl type epoxy compound, naphthol aralkyl type epoxy compound, dicyclopentadiene type epoxy compound, anthracene type epoxy compound, epoxy compound having adamantane skeleton, epoxy compound having tricyclodecane skeleton, naphthylene ether type Epoxy compounds, epoxy compounds having a triazine core in the skeleton, and the like are included.

The epoxy compound preferably contains an epoxy compound having an aromatic skeleton, more preferably contains an epoxy compound having a naphthalene skeleton or a phenyl skeleton, further preferably an epoxy compound having an aromatic skeleton, and a naphthalene skeleton. Particularly preferred is an epoxy compound having In this case, the dielectric loss tangent can be further lowered, and heat resistance, flame retardancy and thermal dimensional stability can be enhanced.

From the viewpoint of further lowering the dielectric loss tangent and improving the coefficient of thermal expansion (CTE), the epoxy compound preferably contains an epoxy compound that is liquid at 25°C and an epoxy compound that is solid at 25°C. .

The viscosity at 25°C of the epoxy compound that is liquid at 25°C is preferably 1000 mPa·s or less, more preferably 500 mPa·s or less.

When measuring the viscosity of the epoxy compound, for example, a dynamic viscoelasticity measuring device (“VAR-100” manufactured by Rheological Instruments Inc.) or the like is used.

More preferably, the epoxy compound has a molecular weight of 1,000 or less. In this case, even if the content of the components excluding the solvent in the resin material is 100% by weight and the content of the inorganic filler is 50% by weight or more, the resin material has high fluidity when forming the insulating layer. Therefore, when an uncured resin material or B-staged resin material is laminated on a circuit board, the inorganic filler can be uniformly present.

The molecular weight of the epoxy compound means the molecular weight that can be calculated from the structural formula when the epoxy compound is not a polymer and when the structural formula of the epoxy compound can be specified. Moreover, when the said epoxy compound is a polymer, it means a weight average molecular weight.

From the viewpoint of further increasing the adhesive strength between the insulating layer and the metal layer, the content of the epoxy compound in 100% by weight of the components excluding the inorganic filler and solvent in the resin material is preferably 5% by weight or more. It is preferably 25% by weight or more, preferably 50% by weight or less, and more preferably 40% by weight or less.

<Maleimide compound>
A conventionally known maleimide compound can be used as the maleimide compound. Only one type of the maleimide compound may be used, or two or more types may be used in combination.

The maleimide compound may be a bismaleimide compound.

Examples of the maleimide compound include N-phenylmaleimide and N-alkylbismaleimide.

The maleimide compound may or may not have an aromatic ring. The maleimide compound preferably has an aromatic ring.

In the above maleimide compound, the nitrogen atom in the maleimide skeleton is preferably bonded to the aromatic ring.

From the viewpoint of further enhancing the thermal dimensional stability, the content of the maleimide compound is preferably 0.5% by weight or more, more preferably 1% by weight or more, based on 100% by weight of the components excluding the solvent in the resin material. It is preferably 15% by weight or less, more preferably 10% by weight or less.

The content of the maleimide compound is preferably 2.5% by weight or more, more preferably 5% by weight or more, and still more preferably 7.5% by weight in 100% by weight of the resin material excluding the inorganic filler and the solvent. % or more, preferably 50% by weight or less, more preferably 35% by weight or less. When the content of the maleimide compound is equal to or more than the lower limit and equal to or less than the upper limit, the thermal dimensional stability of the cured product can be further enhanced.

From the viewpoint of effectively exhibiting the effects of the present invention, the molecular weight of the maleimide compound is preferably 500 or more, more preferably 1000 or more, preferably less than 30,000, and more preferably less than 20,000.

When the maleimide compound is not a polymer and when the structural formula of the maleimide compound can be identified, the molecular weight of the maleimide compound means the molecular weight calculated from the structural formula. When the maleimide compound is a polymer, the molecular weight of the maleimide compound indicates a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

Examples of commercially available maleimide compounds include “BMI-4000” and “BMI-5100” manufactured by Daiwa Kasei Kogyo Co., Ltd., and Designer Molecules Inc. "BMI-3000" and "BMI-1500" manufactured by the company.

[Inorganic filler]
The resin material preferably contains an inorganic filler. The use of the inorganic filler can further reduce the dielectric loss tangent and further improve the thermal dimensional stability. Only one kind of the inorganic filler may be used, or two or more kinds thereof may be used in combination.

Examples of the inorganic filler include silica, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, aluminum nitride, and boron nitride.

The surface roughness of the insulating layer is reduced, the bonding strength between the insulating layer and the metal layer is further increased, finer wiring is formed on the surface of the insulating layer, and the insulating layer has better insulation reliability. From the viewpoint of providing the above, the inorganic filler is preferably silica or alumina, more preferably silica, and still more preferably fused silica. The use of silica further lowers the coefficient of thermal expansion of the insulating layer, effectively reduces the surface roughness of the insulating layer, and effectively increases the bonding strength between the insulating layer and the metal layer. The shape of silica is preferably spherical.

From the viewpoint of promoting curing of the resin, effectively increasing the glass transition temperature of the cured product, and effectively decreasing the thermal linear expansion coefficient of the cured product, regardless of the curing environment, the inorganic filler is spherical silica. is preferred.

The average particle size of the inorganic filler is preferably 10 nm or more, more preferably 50 nm or more, still more preferably 100 nm or more, preferably 5 μm or less, more preferably 3 μm or less, still more preferably 1 μm or less, and particularly preferably 0.5 μm. It is below. When the average particle diameter of the inorganic filler is equal to or more than the lower limit and equal to or less than the upper limit, the adhesion strength between the insulating layer and the metal layer is further increased.

As the average particle diameter of the inorganic filler, a median diameter (d50) of 50% is adopted. The average particle size can be measured using a laser diffraction scattering type particle size distribution analyzer.

The inorganic filler is preferably spherical, more preferably spherical silica. In this case, the surface roughness of the insulating layer is effectively reduced, and the adhesive strength between the insulating layer and the metal layer is effectively increased. When the inorganic filler is spherical, the aspect ratio of the inorganic filler is preferably 2 or less, more preferably 1.5 or less.

The inorganic filler is preferably surface-treated, more preferably surface-treated with a coupling agent, and even more preferably surface-treated with a silane coupling agent. As a result, the surface roughness of the surface of the roughened cured product is further reduced, the adhesive strength between the insulating layer and the metal layer is further increased, finer wiring is formed on the surface of the cured product, and the Better inter-wiring insulation reliability and interlayer insulation reliability can be imparted to the cured product.

Examples of the coupling agent include silane coupling agents, titanium coupling agents and aluminum coupling agents. Examples of the silane coupling agent include methacrylsilane, acrylsilane, aminosilane, imidazolesilane, vinylsilane, and epoxysilane.

The content of the inorganic filler is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, and particularly preferably 60% by weight in 100% by weight of the components excluding the solvent in the resin material. % or more, most preferably 70% or more by weight. The content of the inorganic filler is preferably 90% by weight or less, more preferably 85% by weight or less, still more preferably 83% by weight or less, and particularly preferably 80% by weight in 100% by weight of the components excluding the solvent in the resin material. % by weight or less. When the content of the inorganic filler is not less than the lower limit and not more than the upper limit, the surface roughness of the surface of the cured product is further reduced, the adhesive strength between the insulating layer and the metal layer is further increased, and the cured product is cured. Finer wiring is formed on the surface of the object. Furthermore, with this amount of inorganic filler, it is possible to lower the coefficient of thermal expansion of the cured product and to improve the smear removability. When the content of the inorganic filler is at least the lower limit, the dielectric loss tangent is effectively lowered.

[Curing agent]
The resin material preferably contains a curing agent. The curing agent is not particularly limited. Conventionally known curing agents can be used as the curing agent. Only one kind of the curing agent may be used, or two or more kinds thereof may be used in combination.

The above curing agents include cyanate ester compounds (cyanate ester curing agents), amine compounds (amine curing agents), thiol compounds (thiol curing agents), phosphine compounds, dicyandiamide, phenol compounds (phenol curing agents), acid anhydrides, active Examples include ester compounds, carbodiimide compounds (carbodiimide curing agents), and benzoxazine compounds (benzoxazine curing agents). The curing agent preferably has a functional group capable of reacting with the epoxy group of the epoxy compound.

From the viewpoint of lowering the dielectric loss tangent and enhancing the thermal dimensional stability, the curing agent is at least one selected from phenol compounds, cyanate ester compounds, acid anhydrides, active ester compounds, carbodiimide compounds, and benzoxazine compounds. It preferably contains ingredients. That is, the resin material preferably contains a curing agent containing at least one component selected from a phenol compound, a cyanate ester compound, an acid anhydride, an active ester compound, a carbodiimide compound, and a benzoxazine compound.

In this specification, "at least one component selected from phenol compounds, cyanate ester compounds, acid anhydrides, active ester compounds, carbodiimide compounds, and benzoxazine compounds" may be referred to as "component X".

Therefore, the resin material preferably contains a curing agent containing component X. The resin material more preferably contains a curing agent containing an active ester compound or a phenol compound, and more preferably contains a curing agent containing an active ester compound. The curing agent preferably contains component X, more preferably an active ester compound or a phenol compound, and even more preferably an active ester compound. As for the component X, only one type may be used, or two or more types may be used in combination.

Examples of the phenol compound include novolak-type phenol, biphenol-type phenol, naphthalene-type phenol, dicyclopentadiene-type phenol, aralkyl-type phenol, and dicyclopentadiene-type phenol.

Commercially available products of the above phenol compounds include novolak phenol (manufactured by DIC Corporation "TD-2091"), biphenyl novolak phenol (manufactured by Meiwa Kasei Co., Ltd. "MEH-7851"), aralkyl phenol compounds (manufactured by Meiwa Kasei Co., Ltd. "MEH -7800”), and phenols having an aminotriazine skeleton (manufactured by DIC “LA1356” and “LA3018-50P”).

Examples of the cyanate ester compound include novolak-type cyanate-ester resins, bisphenol-type cyanate-ester resins, and prepolymers obtained by partially trimerizing these. Examples of the novolak-type cyanate ester resins include phenol novolac-type cyanate ester resins and alkylphenol-type cyanate ester resins. Examples of the bisphenol type cyanate ester resin include bisphenol A type cyanate ester resin, bisphenol E type cyanate ester resin and tetramethylbisphenol F type cyanate ester resin.

Commercially available products of the above cyanate ester compounds include phenol novolak type cyanate ester resins (“PT-30” and “PT-60” manufactured by Lonza Japan Co., Ltd.) and prepolymers in which bisphenol type cyanate ester resins are trimerized (Lonza Japan "BA-230S", "BA-3000S", "BTP-1000S" and "BTP-6020S" manufactured by the same company).

Examples of the acid anhydride include tetrahydrophthalic anhydride and alkylstyrene-maleic anhydride copolymer.

Commercially available products of the above acid anhydrides include "Rikashid TDA-100" manufactured by Shin Nippon Rika Co., Ltd., and the like.

The active ester compound is a compound having at least one ester bond in its structure and having aromatic rings bonded to both sides of the ester bond. An active ester compound is obtained, for example, by a condensation reaction between a carboxylic acid compound or a thiocarboxylic acid compound and a hydroxy compound or a thiol compound. Examples of active ester compounds include compounds represented by the following formula (1).

In formula (1) above, X1 represents an aliphatic chain-containing group, an aliphatic ring-containing group, or an aromatic ring-containing group, and X2 represents an aromatic ring-containing group. Preferred examples of the aromatic ring-containing group include an optionally substituted benzene ring and an optionally substituted naphthalene ring. A hydrocarbon group is mentioned as said substituent. The number of carbon atoms in the hydrocarbon group is preferably 12 or less, more preferably 6 or less, still more preferably 4 or less.

The combination of X1 and X2 includes a combination of an optionally substituted benzene ring and an optionally substituted benzene ring, an optionally substituted benzene ring and a substituted A combination with a naphthalene ring optionally having a group is exemplified. Further, the combination of X1 and X2 includes a combination of a naphthalene ring optionally having substituent(s) and a naphthalene ring optionally having substituent(s).

The active ester compound is not particularly limited. From the viewpoint of further enhancing thermal dimensional stability and flame retardancy, the active ester compound is preferably an active ester compound having two or more aromatic skeletons. From the viewpoint of lowering the dielectric loss tangent and improving the thermal dimensional stability, the active ester compound more preferably has a naphthalene ring in the skeleton of the main chain.

Commercially available products of the active ester compound include "HPC-8000-65T", "EXB9416-70BK", "EXB8100-65T", and "HPC-8150-60T" manufactured by DIC.

The carbodiimide compound is a compound having a structural unit represented by the following formula (2). In the following formula (2), the right end and left end are bonding sites with other groups. Only one kind of the carbodiimide compound may be used, or two or more kinds thereof may be used in combination.

In the above formula (2), X is an alkylene group, an alkylene group to which a substituent is bonded, a cycloalkylene group, a cycloalkylene group to which a substituent is bonded, an arylene group, or an arylene group to which a substituent is bonded group, and p is an integer of 1-5. When there are multiple X's, the multiple X's may be the same or different.

In one preferred embodiment, at least one X is an alkylene group, an alkylene group to which a substituent is bonded, a cycloalkylene group, or a cycloalkylene group to which a substituent is bonded.

Commercially available carbodiimide compounds include Nisshinbo Chemical Co., Ltd. "Carbodilite V-02B", "Carbodilite V-03", "Carbodilite V-04K", "Carbodilite V-07", "Carbodilite V-09", "Carbodilite 10M-SP" and "Carbodilite 10M-SP (improved)", and "Stabaxol P", "Stabaxol P400" and "Hykasil 510" manufactured by Rhein Chemie.

Examples of the benzoxazine compound include Pd-type benzoxazine and Fa-type benzoxazine.

Commercially available products of the benzoxazine compound include "Pd type" manufactured by Shikoku Kasei Kogyo Co., Ltd., and the like.

The content of component X is preferably 70 parts by weight or more, more preferably 85 parts by weight or more, preferably 150 parts by weight or less, and more preferably 120 parts by weight or less with respect to 100 parts by weight of the thermosetting compound. be. When the content of component X is above the lower limit and below the upper limit, the curability is further improved, the thermal dimensional stability is further enhanced, and volatilization of residual unreacted components can be further suppressed.

The total content of the thermosetting compound and the component X in 100% by weight of the components excluding the inorganic filler and the solvent in the resin material is preferably 50% by weight or more, more preferably 60% by weight or more, It is preferably 95% by weight or less, more preferably 90% by weight or less. When the total content of the thermosetting compound and the component X is at least the above lower limit and below the above upper limit, the curability is further improved, and the thermal dimensional stability can be further enhanced.

[Curing accelerator]
The resin material preferably contains a curing accelerator. The use of the curing accelerator makes the curing speed even faster. By rapidly curing the resin material, the crosslinked structure in the cured product becomes uniform and the number of unreacted functional groups is reduced, resulting in a high crosslink density. The curing accelerator is not particularly limited, and conventionally known curing accelerators can be used. Only one kind of the curing accelerator may be used, or two or more kinds thereof may be used in combination.

Examples of the curing accelerator include anionic curing accelerators such as imidazole compounds, cationic curing accelerators such as amine compounds, and curing accelerators other than anionic and cationic curing accelerators such as phosphorus compounds and organometallic compounds. , and radical curing accelerators such as peroxides.

Examples of the imidazole compound include 2-undecylimidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl- 2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-un Decylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2' -methylimidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino-6-[2′-undecylimidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino- 6-[2′-ethyl-4′-methylimidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-s -triazine isocyanurate, 2-phenylimidazole isocyanurate, 2-methylimidazole isocyanurate, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-dihydroxymethylimidazole etc.

Examples of the amine compound include diethylamine, triethylamine, diethylenetetramine, triethylenetetramine and 4,4-dimethylaminopyridine.

Examples of the phosphorus compounds include triphenylphosphine compounds.

Examples of the organometallic compounds include zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II) and trisacetylacetonate cobalt (III).

The content of the curing accelerator is not particularly limited. The content of the curing accelerator is preferably 0.01% by weight or more in 100% by weight of components excluding inorganic fillers and solvents in the resin material and 100% by weight of components excluding inorganic fillers in the cured product. , more preferably 0.05% by weight or more, preferably 5% by weight or less, and more preferably 3% by weight or less. When the content of the curing accelerator is equal to or more than the lower limit and equal to or less than the upper limit, the resin material is efficiently cured. If the content of the curing accelerator is within a more preferable range, the storage stability of the resin material will be further increased, and a more favorable cured product will be obtained.

[Thermoplastic resin]
The resin material preferably contains a thermoplastic resin. Examples of the thermoplastic resin include polyvinyl acetal resin, polyimide resin and phenoxy resin. Only one kind of the thermoplastic resin may be used, or two or more kinds thereof may be used in combination.

The thermoplastic resin is preferably a phenoxy resin from the viewpoint of effectively lowering the dielectric loss tangent and effectively increasing the adhesion of the metal wiring regardless of the curing environment. The use of the phenoxy resin suppresses the deterioration of the embedding properties of the resin film in holes or unevenness of the circuit board and the non-uniformity of the inorganic filler. In addition, the use of the phenoxy resin makes it possible to adjust the melt viscosity, so that the dispersibility of the inorganic filler is improved, and during the curing process, the resin material or the B-staged product is less likely to wet and spread in unintended areas.

The phenoxy resin contained in the resin material is not particularly limited. Conventionally known phenoxy resins can be used as the phenoxy resin. Only one type of the phenoxy resin may be used, or two or more types may be used in combination.

Examples of the phenoxy resin include phenoxy resins having a skeleton such as a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a biphenyl skeleton, a novolac skeleton, a naphthalene skeleton and an imide skeleton.

Commercial products of the phenoxy resin include, for example, "YP50", "YP55" and "YP70" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and "1256B40", "4250", "4256H40" manufactured by Mitsubishi Chemical Corporation, " 4275”, “YX6954BH30” and “YX8100BH30”.

From the viewpoint of obtaining a resin material with even better storage stability, the weight average molecular weight of the thermoplastic resin is preferably 5,000 or more, more preferably 10,000 or more, preferably 100,000 or less, and more preferably 50,000 or less.

The weight average molecular weight of the thermoplastic resin indicates the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

The contents of the thermoplastic resin and the phenoxy resin are not particularly limited. The content of the thermoplastic resin (the content of the phenoxy resin when the thermoplastic resin is a phenoxy resin) in 100 wt% of the components excluding the inorganic filler in the resin material is preferably 1 wt% or more, It is more preferably 5% by weight or more, preferably 30% by weight or less, and more preferably 15% by weight or less. When the content of the thermoplastic resin is equal to or more than the lower limit and equal to or less than the upper limit, the embedding property of the resin material into the holes or unevenness of the circuit board is improved. When the content of the thermoplastic resin is equal to or higher than the lower limit, formation of the resin film becomes easier, and an even better insulating layer can be obtained. If the content of the thermoplastic resin is equal to or less than the upper limit, the thermal expansion coefficient of the cured product will be even lower. When the content of the thermoplastic resin is equal to or less than the above upper limit, the surface roughness of the surface of the cured product is further reduced, and the adhesive strength between the insulating layer and the metal layer is further increased.

[solvent]
The resin material does not contain or contains a solvent. By using the solvent, the viscosity of the resin material can be controlled within a suitable range, and the coatability of the resin material can be improved. Also, the solvent may be used to obtain a slurry containing the inorganic filler. Only one of the above solvents may be used, or two or more thereof may be used in combination.

Examples of the solvent include acetone, methanol, ethanol, butanol, 2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 2-acetoxy-1-methoxypropane, toluene, xylene, methyl ethyl ketone, N,N-dimethylformamide, methyl isobutyl ketone, N-methyl-pyrrolidone, n-hexane, cyclohexane, cyclohexanone and mixtures such as naphtha.

Most of the solvent is preferably removed when the resin composition is formed into a film. Therefore, the boiling point of the solvent is preferably 200° C. or lower, more preferably 180° C. or lower. The content of the solvent in the resin composition is not particularly limited. The content of the solvent can be appropriately changed in consideration of the coatability of the resin composition.

[Other ingredients]
For the purpose of improving impact resistance, heat resistance, resin compatibility, workability, etc., the above resin materials contain leveling agents, flame retardants, coupling agents, coloring agents, antioxidants, ultraviolet degradation inhibitors, and anti-degradation agents. Foaming agents, thickeners, thixotropic agents and the like may be added.

Examples of the coupling agent include silane coupling agents, titanium coupling agents and aluminum coupling agents. Examples of the silane coupling agent include vinylsilane, aminosilane, imidazolesilane and epoxysilane.

(resin film and laminated film)
A resin film (B-stage product/B-stage film) is obtained by molding the resin material described above into a film. The resin material is preferably a resin film. The resin film is preferably a B-stage film. By curing the resin film, the film-like cured product can be obtained. The cured product is preferably in the form of a film.

Examples of the method for obtaining a resin film by molding the resin composition into a film include the following methods. An extrusion molding method in which a resin composition is melt-kneaded using an extruder, extruded, and then molded into a film using a T-die, a circular die, or the like. A casting molding method in which a resin composition containing a solvent is cast and molded into a film. Other film forming methods known in the art. An extrusion molding method or a casting molding method is preferable because it can be used for thinning. Film includes sheets.

A resin film that is a B-stage film can be obtained by molding the resin composition into a film and drying it by heating at, for example, 50° C. to 150° C. for 1 minute to 10 minutes to the extent that thermal curing does not proceed excessively. can.

A film-like resin material that can be obtained by the drying process as described above is called a B-stage film. The B-stage film is in a semi-cured state. A semi-cured product is not completely cured and may be further cured.

The resin film may not be a prepreg. If the resin film is not a prepreg, no migration occurs along the glass cloth or the like. In addition, when the resin film is laminated or precured, the unevenness due to the glass cloth does not occur on the surface. The resin film can be used in the form of a laminated film comprising a metal foil or substrate and a resin film laminated on the surface of the metal foil or substrate. The metal foil is preferably copper foil.

The laminated film has a base film and the resin film laminated on the first surface of the base film. A protective film may be laminated on the surface of the resin film opposite to the base film.

Examples of the base film of the laminated film include polyester resin films such as polyethylene terephthalate film and polybutylene terephthalate film, olefin resin films such as polyethylene film and polypropylene film, and polyimide resin films. The surface of the substrate may be subjected to release treatment, if necessary.

From the viewpoint of controlling the degree of curing of the resin film more uniformly, the thickness of the resin film is preferably 5 μm or more and preferably 200 μm or less. When the resin film is used as an insulating layer of a circuit, the thickness of the insulating layer formed of the resin film is preferably equal to or greater than the thickness of the conductor layer (metal layer) forming the circuit. The thickness of the insulating layer is preferably 5 μm or more and preferably 200 μm or less.

(Semiconductor devices, printed wiring boards, copper clad laminates and multilayer printed wiring boards)
The cured product and the B-stage film are used as insulating materials. The cured product and the B-stage film are suitably used as insulating materials in electronic parts such as semiconductor devices, laminates and printed wiring boards.

The resin material, the B-stage film, and the cured product are preferably used to form an insulating layer in a printed wiring board.

The printed wiring board is obtained, for example, by heating and pressurizing the resin material.

A metal foil can be laminated on one side or both sides of the resin film. A method for laminating the resin film and the metal foil is not particularly limited, and a known method can be used. For example, the resin film can be laminated on the metal foil while applying pressure with or without heating using a device such as a parallel plate press or a roll laminator.

The resin material, the B-stage film, and the cured product are preferably used to obtain a copper-clad laminate. An example of the copper-clad laminate is a copper-clad laminate comprising a copper foil and a resin film laminated on one surface of the copper foil.

The thickness of the copper foil of the copper-clad laminate is not particularly limited. The thickness of the copper foil is preferably in the range of 1 μm to 50 μm. In order to increase the adhesive strength between the cured resin material and the copper foil, the copper foil preferably has fine irregularities on its surface. A method for forming the unevenness is not particularly limited. Examples of the method for forming the unevenness include a forming method using a known chemical solution.

The resin material, the B-stage film, and the cured product are preferably used to obtain a multilayer substrate.

An example of the multilayer board is a multilayer board that includes a circuit board and an insulating layer laminated on the circuit board. The material of the insulating layer of this multilayer substrate is the above-described cured body. Moreover, the insulating layer of the multilayer substrate may be formed of the resin film of the laminated film by using the laminated film. The insulating layer is preferably laminated on the surface of the circuit board on which the circuit is provided. A part of the insulating layer is preferably embedded between the circuits.

In the multilayer substrate, it is preferable that the surface of the insulating layer opposite to the surface on which the circuit board is laminated is roughened.

A conventionally known roughening treatment method can be used as the roughening treatment method, and is not particularly limited. The surface of the insulating layer may be subjected to a swelling treatment before the roughening treatment.

Moreover, it is preferable that the multilayer substrate further includes a copper plating layer laminated on the roughened surface of the insulating layer.

Further, as another example of the multilayer board, a circuit board, an insulating layer laminated on the surface of the circuit board, and a surface of the insulating layer laminated on the surface opposite to the surface on which the circuit board is laminated. and a copper foil. The material of the insulating layer of this multilayer substrate is the above-described cured body. It is preferable that the insulating layer is formed by using a copper clad laminate comprising a copper foil and a resin film laminated on one surface of the copper foil, and curing the resin film. Furthermore, the copper foil is preferably etched and is a copper circuit.

Another example of the multilayer board is a multilayer board that includes a circuit board and a plurality of insulating layers laminated on the surface of the circuit board. At least one of the plurality of insulating layers arranged on the circuit board is formed using the resin material. The material of the insulating layer of this multilayer substrate is the above-described cured body. The multilayer substrate preferably further includes a circuit laminated on at least one surface of the insulating layer formed using the resin film.

The resin material, the B-stage film, and the cured product are suitably used for forming an insulating layer in a multilayer printed wiring board.

The multilayer printed wiring board includes, for example, a circuit board, a plurality of insulating layers arranged on the surface of the circuit board, and metal layers arranged between the plurality of insulating layers. The material of at least one insulating layer among the insulating layers is the above-described cured body.

FIG. 1 is a cross-sectional view schematically showing a multilayer printed wiring board using a cured product according to one embodiment of the present invention.

In the multilayer printed wiring board 11 shown in FIG. 1, a plurality of insulating layers 13 to 16 are laminated on the upper surface 12a of the circuit board 12. As shown in FIG. The insulating layers 13 to 16 are hardened layers. A metal layer 17 is formed on a partial region of the upper surface 12 a of the circuit board 12 . A metal layer 17 is formed on a partial region of the upper surface of each of the insulating layers 13 to 15 other than the insulating layer 16 positioned on the outer surface opposite to the circuit board 12 among the multiple insulating layers 13 to 16. It is Metal layer 17 is a circuit. A metal layer 17 is arranged between the circuit board 12 and the insulating layer 13 and between the laminated insulating layers 13 to 16, respectively. The lower metal layer 17 and the upper metal layer 17 are connected to each other by at least one of via-hole connection and through-hole connection (not shown).

In the multilayer printed wiring board 11, the insulating layers 13 to 16 are formed of the cured material. In the multilayer printed wiring board 11, the material of the insulating layers 13 to 16 is the hardened material. In this embodiment, since the surfaces of the insulating layers 13-16 are roughened, fine holes (not shown) are formed in the surfaces of the insulating layers 13-16. Also, the metal layer 17 reaches inside the fine holes. Moreover, in the multilayer printed wiring board 11, the widthwise dimension (L) of the metal layer 17 and the widthwise dimension (S) of the portion where the metal layer 17 is not formed can be reduced. Moreover, in the multilayer printed wiring board 11, good insulation reliability is imparted between the upper metal layer and the lower metal layer that are not connected by via-hole connections and through-hole connections (not shown).

(Roughening treatment and swelling treatment)
The above resin material is preferably used to obtain a cured product that is roughened or desmeared. The cured product also includes a pre-cured product that can be further cured. From the viewpoint of easily forming a sea-island structure, the cured body is preferably a pre-cured body that can be further cured. In order to obtain the pre-cured body, the curing temperature for curing the resin material is preferably 120° C. or higher and 180° C. or lower.

In order to form fine unevenness on the surface of the cured body obtained by precuring the resin material, the cured body is preferably subjected to a roughening treatment. The hardened body is preferably subjected to a swelling treatment before the roughening treatment. It is preferable that the cured product is subjected to a swelling treatment after precuring and before being roughened, and further cured after the roughening treatment. However, the cured body does not necessarily have to be swollen.

As a method for the swelling treatment, for example, a method of treating the cured product with an aqueous solution or an organic solvent dispersion solution of a compound containing ethylene glycol as a main component, or the like is used. The swelling liquid used for the swelling treatment generally contains an alkali as a pH adjuster or the like. The swelling liquid preferably contains sodium hydroxide. Specifically, for example, the swelling treatment is performed by treating the hardened body with a 40% by weight ethylene glycol aqueous solution or the like at a treatment temperature of 30° C. to 85° C. for 1 minute to 30 minutes. The temperature of the swelling treatment is preferably in the range of 50.degree. C. to 85.degree. If the temperature of the swelling treatment is too low, the swelling treatment will take a long time, and the bonding strength between the cured body and the metal layer tends to be low.

A chemical oxidizing agent such as a manganese compound, a chromium compound, or a persulfate compound is used for the roughening treatment. These chemical oxidants are used as aqueous solutions or organic solvent dispersion solutions after water or organic solvents are added. The roughening liquid used for the roughening treatment generally contains an alkali as a pH adjuster or the like. The roughening liquid preferably contains sodium hydroxide.

Examples of the manganese compound include potassium permanganate and sodium permanganate. Examples of the chromium compound include potassium dichromate and anhydrous potassium chromate. Examples of the persulfate compound include sodium persulfate, potassium persulfate and ammonium persulfate.

The surface arithmetic mean roughness Ra of the cured product is preferably 10 nm or more, preferably less than 300 nm, more preferably less than 200 nm, and even more preferably less than 150 nm. In this case, the bonding strength between the insulating layer and the metal layer is increased, and finer wiring is formed on the surface of the insulating layer. Furthermore, conductor loss can be suppressed, and signal loss can be kept low. The arithmetic mean roughness Ra is measured according to JIS B0601:1994.

(Desmear treatment)
Through-holes may be formed in the cured body obtained by pre-curing the resin material. Vias, through holes, or the like are formed as through holes in the multilayer substrates and the like. For example, vias can be formed by irradiation with a laser such as a _CO2 laser. Although the diameter of the via is not particularly limited, it is about 60 μm to 80 μm. Due to the formation of the through-holes, smears, which are residues of the resin derived from the resin component contained in the cured body, are often formed on the bottom of the via.

In order to remove the smear, the surface of the cured body is preferably desmeared. The desmearing treatment may also serve as the roughening treatment.

For the desmear treatment, chemical oxidizing agents such as manganese compounds, chromium compounds, or persulfate compounds are used, as in the roughening treatment. These chemical oxidants are used as aqueous solutions or organic solvent dispersion solutions after water or organic solvents are added. A desmearing liquid used for desmearing generally contains an alkali. The desmear treatment liquid preferably contains sodium hydroxide.

By using the above resin material, the surface roughness of the desmeared insulating layer is sufficiently reduced.

EXAMPLES The present invention will now be described in detail with reference to examples and comparative examples. The invention is not limited to the following examples. In addition, the content of each component described in the table is the weight part of the solid content.

The following materials were prepared.

(Thermosetting compound)
Epoxy compounds:
Biphenyl-type epoxy compound ("NC-3000" manufactured by Nippon Kayaku Co., Ltd.)
Naphthol aralkyl type epoxy compound (“TX-1507B” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
Resorcinol diglycidyl ester ("EX-201" manufactured by Nagase ChemteX Corporation)
Monofunctional epoxy compound (manufactured by Nissan Chemical Co., Ltd. "Foldi-E101")
Dicyclopentadiene type epoxy compound ("EP4088S" manufactured by ADEKA CORPORATION)

Maleimide compounds:
N-alkylbismaleimide compound 1 (Designer Molecules Inc. "BMI-3000")
N-alkylbismaleimide compound 2 (Designer Molecules Inc. "BMI-1500")
N-alkylbismaleimide compound 3 (synthesized in Synthesis Example 1 below)

(Synthesis example 1)
250 mL of toluene was placed in a 500 mL eggplant flask, and 13.2 g (32 mmol) of dimer diamine (“PRIAMINE 1075” manufactured by Croda Japan) and 24.9 g (128 mmol) of tricyclodecanediamine were added. 35.3 g (120 mmol) of biphenylic dianhydride were then added in portions. The eggplant flask was attached to the Dean-Stark apparatus, and the mixture was heated under reflux for 2 hours. Thus, a compound having amines at both ends and multiple imide skeletons was obtained. After removing water discharged during condensation and returning to room temperature, 8.83 g (90 mmol) of maleic anhydride was added, stirred, and heated in the same manner for reaction. Thus, a compound having maleimide skeletons at both ends was obtained. Isopropanol was added to reprecipitate the product. After drying in a vacuum oven, an N-alkylbismaleimide compound 3 was obtained.

(Inorganic filler)
Silica-containing slurry (75% by weight of silica: “SC4050-HOA” manufactured by Admatechs, average particle size 1.0 μm, aminosilane treatment, 25% by weight of cyclohexanone)

(curing agent)
Component X:
Phenolic compound-containing liquid ("LA-1356" manufactured by DIC, solid content 60% by weight)
Liquid containing active ester compound 1 (“EXB-8” manufactured by DIC, solid content 100% by weight)
Liquid containing active ester compound 2 (“HPC8150-62T” manufactured by DIC, solid content 62% by weight)

(Curing accelerator)
Dimethylaminopyridine ("DMAP" manufactured by Wako Pure Chemical Industries, Ltd.)
2-phenyl-4-methylimidazole ("2P4MZ" manufactured by Shikoku Kasei Co., Ltd., anionic curing accelerator)

(Thermoplastic resin)
Phenoxy resin (manufactured by Mitsubishi Chemical Corporation "YX6954BH30")
Polyimide compound 1 (polyimide resin, synthesized in Synthesis Example 2 below)
Polyimide compound 2 (polyimide resin, synthesized in Synthesis Example 3 below)

(Synthesis example 2)
A reaction vessel equipped with a stirrer, a water separator, a thermometer and a nitrogen gas inlet tube was charged with 300.0 g of tetracarboxylic dianhydride ("BisDA-1000" manufactured by SABIC Japan LLC) and 665.5 g of cyclohexanone. and the solution in the reaction vessel was heated to 60°C. Then, 89.0 g of dimer diamine (“PRIAMINE 1075” manufactured by Croda Japan) and 54.7 g of 1,3-bisaminomethylcyclohexane (manufactured by Mitsubishi Gas Chemical Company, Inc.) were dropped into the reaction vessel. Then, 121.0 g of methylcyclohexane and 423.5 g of ethylene glycol dimethyl ether were added to the reactor, and imidization reaction was carried out at 140° C. for 10 hours. Thus, a polyimide compound-containing solution (non-volatile content: 26.8% by weight) was obtained. The obtained polyimide compound 1 had a molecular weight (weight average molecular weight) of 20,000. The molar ratio of acid component/amine component was 1.04.

The molecular weight of polyimide compound 1 synthesized in Synthesis Example 2 was determined as follows.

GPC (gel permeation chromatography) measurement:
Using a high-performance liquid chromatograph system manufactured by Shimadzu Corporation, measurement was performed using tetrahydrofuran (THF) as a developing medium at a column temperature of 40° C. and a flow rate of 1.0 ml/min. "SPD-10A" was used as a detector, and two "KF-804L" columns (exclusion limit molecular weight: 400,000) manufactured by Shodex were connected in series. As standard polystyrene, "TSK Standard Polystyrene" manufactured by Tosoh Corporation was used, and weight average molecular weight Mw = 354,000, 189,000, 98,900, 37,200, 17,100, 9,830, 5,870, 2, A calibration curve was generated using 500, 1,050, 500 substances and molecular weight calculations were performed.

(Synthesis Example 3)
The polyimide compound 1 obtained in Synthesis Example 2 was dissolved in toluene, and then the polymer component was reprecipitated with isopropanol. The obtained polymer was collected by filtration and dried to remove low-molecular-weight components.

(Example 1)
Preparation of resin film:
The components shown in Table 1 below were blended in the amounts shown in Table 1 below (unit: parts by weight of solid content) and stirred at room temperature until a uniform solution was obtained to obtain a resin material.

Using an applicator, apply the obtained resin material on the release-treated surface of a release-treated PET film (“XG284” manufactured by Toray Industries, Inc., thickness 25 μm), and then place in a gear oven at 100° C. for 2 minutes. Dry for 10 seconds to evaporate the solvent. Thus, a laminated film (laminated film of PET film and resin film) in which a resin film (B stage film) having a thickness of 40 μm was laminated on the PET film was obtained.

Preparation of hardened body:
The resulting laminated film is heated stepwise from 130 ° C. to 150 ° C. over 60 minutes to temporarily harden, and then heated at 200 ° C. for 90 minutes to harden to obtain a cured product in which phase separation is suppressed. Obtained. It should be noted that the provisional curing was performed under these conditions also during the production of the evaluation substrates described later.

(Example 2)
Preparation of resin film:
The components shown in Table 1 below were blended in the amounts shown in Table 1 below (unit: parts by weight of solid content) and stirred at room temperature until a uniform solution was obtained to obtain a resin material.

Using an applicator, the obtained resin material is applied onto the release-treated surface of a release-treated PET film ("XG284" manufactured by Toray Industries, Inc., thickness 25 μm), and then placed in a gear oven at 90° C. for 2 minutes. Dry for 30 seconds to evaporate the solvent. Thus, a laminated film (laminated film of PET film and resin film) in which a resin film (B stage film) having a thickness of 40 μm was laminated on the PET film was obtained.

Preparation of hardened body:
The obtained laminate film was temporarily cured by heating at 100° C. for 30 minutes, then at 170° C. for 30 minutes, and then cured by heating at 200° C. for 90 minutes to obtain a cured product. It should be noted that the provisional curing was performed under these conditions also during the production of the evaluation substrates described later.

(Example 3)
Preparation of resin film:
Laminated film (laminated film of PET film and resin film) in the same manner as in Example 2 except that the components shown in Table 1 below were blended in the amounts shown in Table 1 below (unit: parts by weight of solid content) ).

Preparation of hardened body:
The obtained laminate film was temporarily cured by heating at 130° C. for 30 minutes, then at 170° C. for 30 minutes, and then cured by heating at 200° C. for 90 minutes to obtain a cured product. It should be noted that the provisional curing was performed under these conditions also during the production of the evaluation substrates described later. In the reaction of BMI with high compatibility with the epoxy compound and the curing agent, a cured product in which phase separation was suppressed was obtained by aligning the reaction temperature so as to obtain a unimodal peak in DSC measurement.

(Example 4 and Comparative Example 1)
Preparation of resin film:
Laminated film (laminated film of PET film and resin film) in the same manner as in Example 2 except that the components shown in Table 1 below were blended in the amounts shown in Table 1 below (unit: parts by weight of solid content) ).

Preparation of hardened body:
A cured body was obtained in the same manner as in Example 2.

<Preparation of evaluation board>
An evaluation board (an evaluation board comprising a copper-clad laminate and six insulating-wiring circuit composite layers) was prepared as follows. In addition, in the evaluation board, the via holes formed in each layer are continuous. That is, the evaluation board is an evaluation board having multistage stacked vias.

Formation of first insulation-wiring circuit composite layer:
(a1) Lamination step:
A double-sided copper-clad laminate (CCL substrate) (copper foil thickness of 18 μm on each side, substrate thickness of 0.7 mm, substrate size of 100 mm×100 mm, “MCL-E679FG” manufactured by Hitachi Chemical Co., Ltd.) was prepared. Both sides of the copper foil surface of this double-sided copper-clad laminate were immersed in "Cz8101" manufactured by MEC Co., Ltd. to roughen the surface of the copper foil. On both sides of the roughened copper-clad laminate, the resin film (B stage film) side of the laminated film is copper-clad laminated using Meiki Seisakusho's "Batch Type Vacuum Laminator MVLP-500/600-IIA". Laminated on a plate. The lamination conditions were as follows: the pressure was reduced for 30 seconds to an air pressure of 13 hPa or less, and then pressed for 30 seconds at 100° C. and a pressure of 0.4 MPa. After peeling off the PET film, the resin film was semi-cured (pre-cured) by heating under the temporary curing conditions used in the production of the above-described cured body. Thus, a laminate (1) in which the semi-cured resin film was laminated on the CCL substrate was obtained.

(b1) Via hole forming step:
Using a CO ₂ laser processing machine (“LC-4KF212” manufactured by Via Mechanics Co., Ltd.), a via hole with a diameter of about 60 μm was formed under the conditions of burst mode, energy of 0.4 mJ, pulse of 27 μsec, and 3 shots.

(c1) Desmear treatment and roughening treatment:
(c1-1) swelling treatment:
The resulting laminate (1) was placed in a swelling liquid (“Swelling Dip Securigant P” manufactured by Atotech Japan Co., Ltd.) at 60° C. and shaken for 10 minutes. After that, it was washed with pure water.

(c1-2) permanganate treatment (roughening treatment and desmear treatment):
The laminate (1) after the swelling treatment was placed in a roughening aqueous solution of potassium permanganate (“Concentrate Compact CP” manufactured by Atotech Japan) at 80° C. and shaken for 30 minutes. Next, it was treated for 2 minutes with a cleaning liquid (“Reduction Securigant P” manufactured by Atotech Japan Co., Ltd.) at 25° C., and then washed with pure water to obtain a laminate (1) after roughening treatment.

(c1-3) Measurement of surface roughness:
The surface of the laminate (1) after the roughening treatment (roughening-treated cured product) was measured using a non-contact three-dimensional surface profile measuring device (“Contour GT-K” manufactured by Bruker) to 95.6 μm × Arithmetic mean roughness Ra was measured over a measurement area of 71.7 μm. The arithmetic mean roughness Ra was measured according to JIS B0601:1994. It was confirmed that the surface roughness of the surface of the roughened cured product was 200 nm or less.

(d1) Electroless plating treatment:
The surface of the cured laminate (1) after the roughening treatment was treated with an alkaline cleaner (“Cleaner Securigant 902” manufactured by Atotech Japan Co., Ltd.) at 60° C. for 5 minutes to be degreased and washed. After washing, the cured product was treated with a pre-dip liquid ("Pre-dip Neogant B" manufactured by Atotech Japan Co., Ltd.) at 25°C for 2 minutes. Thereafter, the cured product was treated with an activator liquid (“Activator Neogant 834” manufactured by Atotech Japan Co., Ltd.) at 40° C. for 5 minutes to attach a palladium catalyst. Next, the cured product was treated with a reducing liquid (“Reducer Neogant WA” manufactured by Atotech Japan Co., Ltd.) at 30° C. for 5 minutes.

Next, the cured product is placed in a chemical copper solution ("Basic Printgant MSK-DK", "Copper Printgant MSK", "Stabilizer Printgant MSK", and "Reducer Cu" manufactured by Atotech Japan Co., Ltd.) for electroless plating. was carried out until the plating thickness reached about 0.5 μm. After electroless plating, an annealing treatment was performed at a temperature of 120° C. for 30 minutes in order to remove residual hydrogen gas. All the steps up to the step of electroless plating were carried out with a beaker scale of 2 liters of the processing liquid, while shaking the cured product.

(e1) Resist formation:
A dry film resist (“RY5125” manufactured by Hitachi Chemical Co., Ltd.) was attached using a hot roll laminator. The lamination conditions were a temperature of 100° C., a pressure of 0.4 MPa and a lamination speed of 1.5 m/min, and then held for 15 minutes. Then, after exposure at 85 mJ/cm ² , development was carried out by spraying a 1 wt % sodium carbonate aqueous solution at 27° C. under a spray pressure of 1.2 MPa for 30 seconds.

(f1) Electroplating treatment:
Next, the electroless-plated cured product was electroplated until the plating thickness reached 25 μm. As electrolytic copper plating, copper sulfate solution (“Copper sulfate pentahydrate” manufactured by Wako Pure Chemical Industries, “Sulfuric acid” manufactured by Wako Pure Chemical Industries, Ltd. “Basic Leveler Cupalaside HL” manufactured by Atotech Japan, “ Electroplating was carried out using a correction agent "Capalacid GS") and applying a current of 0.6 A/cm ² until the plating thickness reached about 25 μm.

(g1) DFR stripping and etching treatment:
The dry film resist (DFR) was removed by spraying with a 3 wt % sodium hydroxide aqueous solution. Next, quick etching was performed with a perhydrate sulfuric acid-based acidic etchant (“SAC Process” manufactured by JCU).

(h1) main curing step:
Heat to peak temperature T at 190° C. for 1.5 hours.

In this manner, a first insulation-wiring circuit composite layer was formed on the copper-clad laminate.

Formation of the second insulation-wiring circuit composite layer:
(a2) Lamination step:
(a1) The first wiring circuit layer was subjected to roughening treatment under the same roughening treatment conditions as in the lamination step. Then, the resin film (B stage film) side of the laminated film was laminated on the first insulating-wiring circuit composite layer under the laminating conditions used in the (a1) laminating step. Then, after removing the PET film, the resin film was semi-cured by heating at 130° C. for 60 minutes. Thus, a laminate (2) was obtained in which the semi-cured resin film was laminated on the first insulating-wiring circuit composite layer.

(b2) Via hole forming step:
(b1) A via hole was formed in the same manner as in the step of forming a via hole, except that the laminated body (1) was changed to the laminated body (2).

(c2) desmear treatment and roughening treatment:
(c1) Laminate (2) after roughening treatment was obtained in the same manner as the steps performed in desmear treatment and roughening treatment, except that laminate (1) was changed to laminate (2).

(d2) Electroless plating treatment:
(d1) Electroless plating was performed in the same manner as in the electroless plating process, except that the roughened laminate (1) was changed to the roughened laminate (2). rice field.

(f2) Electroplating treatment:
(d2) After performing the electroless plating treatment, electroless plating treatment was performed in the same manner as in (f1) electroplating treatment.

(h2) Main curing step:
(h1) Heating was performed at 190° C. for 1.5 hours in the same manner as in the main curing step.

In this manner, a second insulation-wiring circuit composite layer was formed on the first insulation-wiring circuit composite layer.

Formation of the third insulation-wiring circuit composite layer:
A third insulation-wiring circuit composite layer was formed on the second insulation-wiring circuit composite layer in the same manner as the step of forming the second insulation-wiring circuit composite layer.

Formation of the fourth insulation-wiring circuit composite layer:
A fourth insulation-wiring circuit composite layer was formed on the third insulation-wiring circuit composite layer in the same manner as the step of forming the second insulation-wiring circuit composite layer.

Formation of the 5th insulation-wiring circuit composite layer:
(a5) Lamination step:
(a2) A laminate (5) was obtained in which a semi-cured resin film was laminated on the fourth insulation-wiring circuit composite layer in the same manner as in the lamination step.

(b5) Via hole forming step:
(b1) A via hole was formed in the same manner as in the step of forming a via hole, except that the laminated body (1) was changed to the laminated body (5).

(c5) Desmear treatment and roughening treatment:
(c1) Laminate (5) after roughening treatment was obtained in the same manner as the steps performed in desmear treatment and roughening treatment, except that laminate (1) was changed to laminate (5).

(d5) Electroless plating treatment:
(d1) Electroless plating was performed in the same manner as in the electroless plating process, except that the roughened laminate (1) was changed to the roughened laminate (5). rice field.

(e5) resist formation:
(e1) Development was performed in the same manner as in the resist formation step.

(f5) Electroplating treatment:
After the dry film resist pattern was formed, electroless plating was performed in the same manner as (f1) electrolytic plating.

(g5) DFR stripping and etching treatment:
(g1) DFR stripping and etching were performed in the same manner as in the DFR stripping and etching.

(h5) Main curing step:
(h1) Heating was performed at 190° C. for 1.5 hours in the same manner as in the main curing step.

In this manner, the fifth insulation-wiring circuit composite layer was formed on the fourth insulation-wiring circuit composite layer.

Formation of the 6th insulation-wiring circuit composite layer:
A sixth insulation-wiring circuit composite layer was formed on a fifth insulation-wiring circuit composite layer in the same manner as the step of forming the second insulation-wiring circuit composite layer.

In this way, an evaluation board was produced in which the first to sixth insulation-wiring circuit composite layers were formed on the copper-clad laminate. In the obtained evaluation board, only the 1st and 5th wiring circuit layers among the 1st to 6th wiring circuit layers have patterns.

(evaluation)
(1) Measurement by pulse NMR The obtained cured body was cut into a length of 2 cm and introduced into a glass sample tube with a diameter of 10 mm (manufactured by BRUKER, product number 1824511, length 180 mm, flat bottom). The sample tube was placed in a pulse NMR apparatus (“the minispec mq20” manufactured by BRUKER), and the temperature was maintained at 30°C (10 minutes retention), 70°C (10 minutes retention), 100°C (10 minutes retention), 150°C (10 minutes retention). ) and 170° C. (held for 10 minutes).

At 30° C. and 170° C., measurement was performed by the Solid Echo method under the following conditions to obtain a free induction decay curve of spin-spin relaxation of ¹ H.

<Solid Echo Method>
Scans: 128 times
Recycle Delay: 1sec
Acquisition scale: 1.0ms

The free induction decay curve of spin-spin relaxation of ¹ H obtained was waveform-separated into three curves derived from three components, hard component, middle component and soft component. Waveform separation was performed by fitting using both the Gaussian type and the exponential type. The ratio of each component was obtained from the curves derived from the three components obtained in each measurement.

In addition, using BRUKER's analysis software "TD-NMRA (Version 4.3 Rev 0.8)", according to the product manual, fitting was performed with the Gaussian type for the hard component and the exponential type for the middle component and the soft component. rice field. In the analysis, fitting was performed using points up to 0.6 msec on the relaxation curve to obtain the amount of each component and the relaxation time.

In addition, fitting was performed using the following formula (X).

Y=A1*exp(-1/w1*(t/T2A)^w1)+B1*exp(-1/w2*(t/T2B)^w2)+C1*exp(-1/w3*(t/T2C) ^w3) Expression (X)

In the above formula (X), w1, w2, and w3 are Weibull coefficients, w1 is 2, and w2 and w3 are 1. In the above formula (X), A1 is the content of the hard component, B1 is the content of the middle component, C1 is the content of the soft component, T2A is the relaxation time of the hard component, and T2B is the middle component. is the relaxation time of the component and T2C is the relaxation time of the soft component. In the above formula (X), t is time.

The following was obtained by performing the above pulse NMR measurement and the above analysis using the obtained cured product.

Content (%) of the soft component at 30°C in the total 100% of the content of the hard component at 30°C, the content of the middle component at 30°C, and the content of the soft component at 30°C
Content (%) of the soft component at 170°C in the total 100% of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C
Spin-spin relaxation time (ms) of the soft component at 30°C
Spin-spin relaxation time of the soft component at 170°C (ms)

(2) Curvature of Cured Body The obtained laminate film was cut into a size of 50 mm×50 mm. The cut laminated film is overlaid on a copper plate (50 mm × 50 mm × thickness 100 μm) from the resin film side, and a diaphragm type vacuum laminator ("Batch type vacuum laminator MVLP-500-IIA" manufactured by Meiki Seisakusho Co., Ltd.) is used. After reducing the pressure to 13 hPa or less for a second, lamination was performed at 100° C. and a pressure of 0.7 MPa for 30 seconds. Thus, a laminate was obtained in which the laminated film (the uncured resin film and the PET film) was laminated on the copper plate.

The PET film was peeled off, and the obtained laminate was heated under the temporary curing conditions used in the preparation of the above-described cured body. Then, it was heated at 200° C. for 90 minutes. In this way, a laminate was obtained in which the cured product (cured product) of the resin film was laminated on the copper plate. The laminate was placed on flat glass so that the copper plate was on the bottom side and the cured product was on the top side, and how much the four corners were warped was measured. Each distance from the upper surface of the flat glass to four corners was defined as the amount of warp, and the average value of the amount of warp at the four corners was obtained. Curvature of the cured product was determined according to the following criteria.

[Criteria for determining warpage of cured body]
○○: The average value of the warp amount is 3 mm or less ○: The average value of the warp amount is more than 3 mm and 5 mm or less △: The average value of the warp amount is more than 5 mm and 10 mm or less ×: The average value of the warp amount is more than 10 mm

(3) Cracks or Cracks in Insulating Layer The obtained evaluation substrates were subjected to a liquid tank thermal shock test (thermal cycle test) under the following two conditions.

Test condition 1: -55°C to 125°C, 5 minutes each, 1000 cycles Test condition 2: -65°C to 150°C, 5 minutes each, 1000 cycles

Using a scanning electron microscope (SEM), the insulating layer around the via hole was observed on the evaluation substrate subjected to the liquid bath thermal shock test. In addition, the insulating layer and the wiring circuit layer in the regions other than the vicinity of the via hole were also observed.

[Criteria for cracking or cracking of insulating layer (around via hole)]
○: No cracks or cracks in the insulating layer around the via hole ×: Cracks or cracks in the insulating layer around the via hole

[Criteria for cracks or cracks in insulating layer (other than around via holes)]
○: No cracks or cracks in the insulating layer in the region other than the via hole ×: Cracks or cracks in the insulating layer in the region other than the via hole

Moreover, no cracks or cracks in the wiring circuit layer were observed in the evaluation substrates obtained in the examples.

Compositions and results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 11... Multilayer printed wiring board 12... Circuit board 12a... Upper surface 13-16... Insulating layer 17... Metal layer

Claims (10)

A cured body of a resin material,
A cured product used as an insulating material,
Based on the free induction decay curve at 170 ° C. obtained using pulse NMR, the components contained in the cured body are classified in order of shortest spin-spin relaxation time: hard component at 170 ° C., middle component at 170 ° C. , when separated into three components of the soft component at 170° C.,
In the total 100% of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C, the content of the soft component at 170°C is A cured product having a content of 5% or more and 40% or less. In the total 100% of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C, the content of the soft component at 170°C is 2. The cured body according to claim 1, which is 10% or more and 25% or less. Based on the free induction decay curve at 30 ° C. obtained using pulse NMR, the components contained in the cured body are classified in order of shortest spin-spin relaxation time: hard component at 30 ° C., middle component at 30 ° C. , when separated into three components of the soft component at 30° C.,
The content of the soft component at 170°C in the total 100% of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C , the content of the soft component at 30°C in the total 100% of the content of the hard component at 30°C, the content of the middle component at 30°C, and the content of the soft component at 30°C 3. The cured body according to claim 1 or 2, wherein the ratio to is 2 or more and 30 or less. The cured body according to any one of claims 1 to 3, wherein the resin material contains a thermosetting compound and an inorganic filler. The resin material contains a thermosetting compound and a curing agent,
the thermosetting compound comprises an epoxy compound,
The cured product according to any one of claims 1 to 3, wherein the curing agent contains an active ester compound. A B-stage film,
A B-stage film used as an insulating material,
The B-stage film was heated at 130° C. for 30 minutes, 170° C. for 30 minutes, and 200° C. for 1 hour in this order to obtain a cured B-stage film, and the free-form at 170° C. obtained using pulse NMR. Based on the induced decay curve, the components contained in the cured product are separated into three components in descending order of spin-spin relaxation time: a hard component at 170°C, a middle component at 170°C, and a soft component at 170°C. when
The content of the soft component at 170°C in the total 100% of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C A B-stage film that is 5% or more and 40% or less. In the total 100% of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C, the content of the soft component at 170°C is 7. The B-stage film of claim 6, which is 10% or more and 25% or less. Based on the free induction decay curve at 30 ° C. obtained using pulse NMR, the components contained in the cured body are classified in order of shortest spin-spin relaxation time: hard component at 30 ° C., middle component at 30 ° C. , when separated into three components of the soft component at 30° C.,
The content of the soft component at 170°C in the total 100% of the content of the hard component at 170°C, the content of the middle component at 170°C, and the content of the soft component at 170°C , the content of the soft component at 30°C in the total 100% of the content of the hard component at 30°C, the content of the middle component at 30°C, and the content of the soft component at 30°C 8. The B-stage film of claim 6 or 7, wherein the ratio to is 2 or more and 30 or less. The B-stage film according to any one of claims 6 to 8, which is used for forming an insulating layer in a multilayer printed wiring board. a circuit board;
a plurality of insulating layers disposed on the surface of the circuit board;
A metal layer disposed between the plurality of insulating layers,
A multilayer printed wiring board, wherein the material of at least one insulating layer among the plurality of insulating layers is the cured body according to any one of claims 1 to 5.

Images