JP5351910B2 - B-stage film and multilayer substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin material in which the heat dimensional change of a cured product after curing can be made small, in addition the roughness uniformity of a roughening processed surface of the cured product can be raised, and to provide a multilayer board using the epoxy resin material. <P>SOLUTION: The epoxy resin material includes an epoxy resin, and a curing agent. The curing agent is a cyanate curing agent including: a tetramethyl bisphenol F type dicyanate; and at least one in a polymer of a polymerization component including the tetramethyl bisphenol F type dicyanate. The multilayer board 11 includes: a circuit board 12; and cured material layers 13-16 arranged on a surface 12a on which a circuit of the circuit board 12 is formed. The cured material layer 13-16 are formed by curing the epoxy resin material. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an epoxy resin material that can be used, for example, to form an insulating layer in a multilayer substrate, and more specifically, an epoxy resin material containing an epoxy resin and a curing agent, and the epoxy resin material. Related to the multilayer substrate.

  Conventionally, various resin compositions have been used to obtain electronic components such as laminates and printed wiring boards. For example, in a multilayer printed wiring board, a resin composition is used in order to form an insulating layer for insulating inner layers or to form an insulating layer located in a surface layer portion.

  As an example of the resin composition, the following Patent Document 1 includes a cyanate ester resin represented by the following formula (101), an epoxy resin, a polymer resin, a curing catalyst, and an inorganic filler. A composition is disclosed. Here, it is described that it is possible to form a plated conductor layer having sufficient adhesion strength while the coefficient of thermal expansion of the insulating layer formed after thermosetting is low and the surface of the insulating layer has low roughness. .

  In said formula (101), n shows the number of 1-6 as an average value, X shows a glycidyl group or a C1-C8 hydrocarbon group, and the ratio of hydrocarbon group / glycidyl group is 0.05- 2.0.

  Patent Document 2 below discloses a resin composition containing an adduct body of an epoxy resin, a cyanate ester resin, a guanidine compound and an epoxy resin, a metal-based curing catalyst, and an inorganic filler. Here, it is described that the insulating layer has a low coefficient of thermal expansion, can form a uniform roughened surface with low roughness on the surface of the insulating layer, and can improve the adhesion of the conductor layer formed on the roughened surface. Yes.

WO2008 / 044766A1 JP 2010-90237 A

  The insulating layer of the multilayer printed wiring board is strongly required to hardly peel off from other insulating layers or circuits laminated on the insulating layer. For this reason, in the said insulating layer, it is desired that a dimension does not change a lot with heat. That is, it is desirable that the insulating layer has a low coefficient of linear expansion.

  In recent years, as the density of a package increases, a substrate used in the package is easily warped. For this reason, the request | requirement which makes the curvature of a board | substrate small is increasing very much. In order to sufficiently suppress the warpage of the substrate, it is necessary to reduce the linear expansion coefficient of the insulating layer stacked on the substrate.

  As described in Patent Documents 1 and 2, when a cyanate ester resin is used, the dimensional change due to heat of the insulating layer can be made relatively small, and the linear expansion coefficient of the insulating layer can be made relatively low. be able to. However, in recent years, it has been required to further reduce the dimensional change due to heat of the cured product and to further increase the linear expansion coefficient of the insulating layer.

  Furthermore, an insulating layer is formed using a conventional resin composition as described in Patent Documents 1 and 2 on a member such as a circuit board on which a metal layer is partially provided on the upper surface, and the insulation is further performed. When the surface of the layer is roughened, unevenness may occur in the roughness of the roughened surface of the insulating layer. That is, the roughness may be different between the insulating layer located in the portion where the metal layer is provided and the insulating layer located in the portion where the metal layer is not provided. If the roughness is uneven, there is a problem that when another metal layer is formed on the insulating layer, the adhesive strength between the insulating layer and the other metal layer is partially lowered.

  An object of the present invention is to provide an epoxy resin material capable of reducing the dimensional change due to heat of a cured product after curing, and further improving the uniformity of the roughness of the roughened surface of the cured product, and the A multilayer substrate using an epoxy resin material is provided.

  A limited object of the present invention is to provide an epoxy resin material capable of enhancing storage stability, and a multilayer substrate using the epoxy resin material.

  A further limited object of the present invention is to provide an epoxy resin material capable of setting the arithmetic average roughness Ra of the roughened surface of the cured product to 200 nm or less, and a multilayer substrate using the epoxy resin material. That is.

  According to a wide aspect of the present invention, an epoxy resin and a curing agent are contained, and the curing agent includes tetramethylbisphenol F type dicyanate and a polymer of a polymerization component including the tetramethylbisphenol F type dicyanate. An epoxy resin material is provided that is a cyanate curing agent comprising at least one of the following:

  On the specific situation with the epoxy resin material which concerns on this invention, content of the said cyanate hardening | curing agent is 5 to 30 weight% in the total 100 weight% of all the resin components in this epoxy resin material.

  In another specific aspect of the epoxy resin material according to the present invention, the total of the cyanate curing agent is 100% by weight of the tetramethylbisphenol F type dicyanate and a polymer of a polymerization component containing the tetramethylbisphenol F type dicyanate. The total content is 1% by weight or more and 70% by weight or less.

  In another specific aspect of the epoxy resin material according to the present invention, an inorganic filler is further contained.

  In still another specific aspect of the epoxy resin material according to the present invention, the content of the inorganic filler is 40% by weight or more and 80% by weight or less in 100% by weight of the total solid content in the epoxy resin material.

  In still another specific aspect of the epoxy resin material according to the present invention, the inorganic filler is silica.

  In another specific aspect of the epoxy resin material according to the present invention, a thermoplastic resin is further contained.

  In still another specific aspect of the epoxy resin material according to the present invention, the content of the thermoplastic resin is 1 wt% or more and 30 wt% or less in a total of 100 wt% of all resin components in the epoxy resin material. .

  In still another specific aspect of the epoxy resin material according to the present invention, the thermoplastic resin is a phenoxy resin.

  In another specific aspect of the epoxy resin material according to the present invention, a curing accelerator is not contained or contained, and when a curing accelerator is contained, the total resin component in the epoxy resin material is 100 weights in total. %, The content of the curing accelerator is 1% by weight or less.

  In still another specific aspect of the epoxy resin material according to the present invention, the epoxy resin material is a B-stage film formed into a film shape.

  In still another specific aspect of the epoxy resin material according to the present invention, the epoxy resin material is an epoxy resin material used for obtaining a cured product to be roughened or desmeared.

  A multilayer board according to the present invention includes a circuit board and a cured product layer disposed on the surface of the circuit board, and the cured product layer cures the epoxy resin material configured according to the present invention. It is formed by.

  The epoxy resin material according to the present invention contains an epoxy resin and a curing agent, and the curing agent is tetramethylbisphenol F type dicyanate and a polymer of polymerization components including the tetramethylbisphenol F type dicyanate. Since it is a cyanate curing agent containing at least one kind, the dimensional change due to heat of the cured product after curing can be reduced, and the uniformity of the roughness of the roughened surface of the cured product can be further increased. .

FIG. 1 is a partially cutaway front sectional view schematically showing a multilayer substrate using an epoxy resin material according to an embodiment of the present invention. FIG. 2 is a schematic partial cutaway front sectional view for explaining the roughness on the surface of the cured product layer using the epoxy resin material.

  Details of the present invention will be described below.

(Epoxy resin material)
The epoxy resin material according to the present invention contains an epoxy resin and a curing agent. The curing agent is a cyanate curing agent containing at least one of tetramethylbisphenol F type dicyanate and a polymer of a polymerization component containing the tetramethylbisphenol F type dicyanate. The polymer of the polymerization component containing the tetramethylbisphenol F type dicyanate is a tetramethylbisphenol F type dicyanate ester resin. The tetramethylbisphenol F type dicyanate is a compound that gives the tetramethylbisphenol F type dicyanate ester resin by polymerization.

  By adopting the above composition, the dimensional change due to heat of the cured product after curing can be reduced, and the uniformity of the roughness of the roughened surface of the cured product can be further increased. For example, as shown in FIG. 2, a cured product layer 3 is formed using an epoxy resin material on a circuit board 1 in which the metal layer 2 is partially provided on the upper surface 1 a, and the cured product layer 3 is further formed. When the surface 3a is roughened, unevenness in the roughness of the roughened surface 3a of the cured product layer 3 can be made difficult to occur. That is, the uniformity of the roughness of the surface 3a is enhanced by the cured product layer 3A located in the portion where the metal layer 2 is provided and the cured product layer 3B located in the portion where the metal layer 2 is not provided. Can do. In particular, when the metal layer 2 is a copper layer, the effect of increasing the uniformity of the roughness is further enhanced. This is because the metal layer 2 such as a copper layer acts as a catalyst, so that the effect of increasing the curing speed when forming the cured product layer 3 on the metal layer 2 is considered.

  When the roughness of the roughened surface 3a is high, when the metal layer is formed on the roughened surface 3a of the cured product layer 3, the adhesive strength between the cured product layer 3 and the metal layer is increased. Partial lowering can be suppressed. Furthermore, if the roughness of the roughened surface 3a of the cured product layer 3 is uniform, etching is performed as necessary when another metal layer is formed on the roughened surface 3a by plating. The other metal layer can also be effectively removed partially.

  Further, according to the present invention, it is easy to make the entire surface 3a subjected to the roughening treatment of the cured product layer 3 a surface having a uniform roughness with an arithmetic average roughness Ra of 200 nm or less.

  Furthermore, by adopting the above composition, the storage stability of the epoxy resin material at room temperature (24 ° C.) is also increased. The use of the specific cyanate curing agent greatly contributes to the improvement in storage stability of the epoxy resin material at room temperature. Furthermore, in the epoxy resin material of the present invention, it is not necessary to use a curing accelerator, and even when a curing accelerator is used, the amount of the curing accelerator used can be reduced. It is possible to increase. In addition, there exists a tendency for the storage stability of an epoxy resin material to become low, so that there is much usage-amount of a hardening accelerator. In order to obtain a good B-stage film, it is preferable to use a curing accelerator.

  From the viewpoint of further reducing the surface roughness of the roughened cured product and further improving the uniformity of the surface roughness, the epoxy resin material according to the present invention contains an inorganic filler. It is preferable. In addition, in an epoxy resin material containing an epoxy resin and a curing agent, by adding a large amount of inorganic filler such as silica, the dimensional change due to heat of the cured product can be further reduced, that is, the linear expansion coefficient is lowered. can do. In addition, by using an inorganic filler, finer pores can be formed on the roughened surface of the cured product. As a result, the peel strength of the metal layer provided on the roughened surface of the cured product is increased. It can be further increased.

  Further, by using the epoxy resin material according to the present invention, for example, a cured product layer 3A located in a portion where the metal layer 2 shown in FIG. 2 is provided, and a cure located in a portion where the metal layer 2 is not provided. The presence state of the inorganic filler can be made uniform with the physical layer 3B.

  The epoxy resin material according to the present invention preferably contains a thermoplastic resin, and more preferably contains a phenoxy resin.

  The epoxy resin material according to the present invention may be a paste or a film. The epoxy resin material according to the present invention may be a resin composition or a B-stage film in which the resin composition is formed into a film.

  Hereinafter, details of each component such as an epoxy resin and a curing agent contained in the epoxy resin material according to the present invention, and an inorganic filler and a thermoplastic resin that can be used in the epoxy resin material according to the present invention will be described.

[Epoxy resin]
The epoxy resin contained in the epoxy resin material is not particularly limited. A conventionally well-known epoxy resin can be used as this epoxy resin. The epoxy resin refers to an organic compound having at least one epoxy group. As for an epoxy resin, only 1 type may be used and 2 or more types may be used together.

  Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, biphenyl novolac type epoxy resin, biphenol type epoxy resin, naphthalene type epoxy resin, and fluorene type epoxy resin. , Phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, anthracene type epoxy resin, epoxy resin having adamantane skeleton, epoxy resin having tricyclodecane skeleton, and epoxy resin having triazine nucleus in skeleton Etc.

  From the viewpoint of further reducing the surface roughness of the roughened or desmeared cured product, the epoxy equivalent of the epoxy resin is preferably 90 or more, more preferably 100 or more, preferably 1000 or less, more Preferably it is 800 or less.

  The epoxy resin preferably has a weight average molecular weight of 1000 or less. In this case, the content of the inorganic filler in the epoxy resin material can be increased. Furthermore, even if there is much content of an inorganic filler, the resin composition which is an epoxy resin material with high fluidity | liquidity can be obtained. On the other hand, the combined use of an epoxy resin having a weight average molecular weight of 1000 or less and a thermoplastic resin such as a phenoxy resin can suppress a decrease in the melt viscosity of the B stage film that is an epoxy resin material. For this reason, when a B stage film is laminated on a board | substrate, an inorganic filler can be made to exist uniformly.

  The content of the epoxy resin is preferably 20% by weight or more, more preferably 30% in 100% by weight of the total resin components (hereinafter, may be abbreviated as total resin component X) contained in the epoxy resin material. % By weight or more, preferably 80% by weight or less, more preferably 70% by weight or less. When the content of the epoxy resin is not less than the above lower limit and not more than the above upper limit, the surface roughness of the surface of the roughened cured product can be further reduced, and the surface of the cured product roughened. The peel strength of the metal layer provided above becomes even better. “Total resin component X” refers to the total of the epoxy resin, the cyanate curing agent, and other resin components blended as necessary. The total resin component X does not include an inorganic filler.

[Curing agent]
The curing agent contained in the epoxy resin material is a cyanate curing agent containing at least one of tetramethylbisphenol F type dicyanate and a polymer of a polymerization component containing the tetramethylbisphenol F type dicyanate (hereinafter, It may be described as cyanate curing agent A). The use of the cyanate curing agent A greatly contributes to reducing the dimensional change due to heat of the cured product after curing and increasing the uniformity of the roughness of the roughened surface of the cured product. Cyanate curing agent A includes all cyanate curing agents in the epoxy resin material. The cyanate curing agent A may contain only tetramethylbisphenol F-type dicyanate, or may contain only a polymer of a polymerization component containing the tetramethylbisphenol F-type dicyanate. It may contain both the polymer of the polymerization component containing tetramethylbisphenol F type dicyanate.

  The tetramethylbisphenol F type dicyanate is preferably a tetramethylbisphenol F type dicyanate represented by the following formula (1). In addition, in following formula (1), the coupling | bond part of four methyl groups couple | bonded with the benzene ring is not specifically limited.

  From the viewpoint of ease of synthesis, the tetramethylbisphenol F type dicyanate represented by the above formula (1) is preferably a tetramethylbisphenol F type dicyanate represented by the following formula (1A).

  When the cyanate curing agent A is used, since four methyl groups are bonded to the benzene ring, steric hindrance exists around the triazine ring generated in the curing process, and the planar linearity is lowered. For this reason, the curability of the cured product is improved. The cyanate curing agent A has a bisphenol F-type skeleton, and the bisphenol F-type skeleton has high flexibility. Accordingly, the flexibility of the cured product is increased, and as a result, the peel strength of the metal layer provided on the roughened surface of the cured product is improved.

  Further, since the cyanate curing agent A has a bisphenol F-type skeleton, it has a relatively high curability and contributes to a rapid progress of curing of the epoxy resin material. Therefore, the epoxy resin material according to the present invention may or may not contain a curing accelerator. By using the cyanate curing agent A, even if the content of the curing accelerator is 0% by weight or more and 1% by weight or less in the total 100% by weight of all resin components in the epoxy resin material, Curing can proceed quickly. By not using the curing accelerator or reducing the amount of the curing accelerator used, the storage stability of the epoxy resin material can be further enhanced.

  On the other hand, conventionally, a bisphenol A type dicyanate ester resin in which a methyl group is not bonded to a benzene ring is known as a curing agent. When this curing agent is used, the triazine ring generated in the curing process has a planar line shape, so that it is easy to take a stack structure, good crystallinity, and generally not very hard. For this reason, when a bisphenol A type dicyanate ester resin in which a methyl group is not bonded to a benzene ring is used, there is a tendency that unevenness of the roughened surface of the cured product tends to occur.

  Conventionally, in general, when a cured product layer (insulating layer) is formed using an epoxy resin material on a circuit board partially provided with a metal layer such as a copper circuit, there is a metal layer. There is a tendency for the degree of cure to be different between the cured product layer provided in the part and the cured product layer provided in the part without the metal layer. On the other hand, by using the epoxy resin material according to the present invention containing the specific cyanate curing agent A, a cured product layer provided in a portion with a metal layer and a cured product provided in a portion without a metal layer. It becomes difficult to produce a difference in the degree of curing between the layers. As a result, the uniformity of the roughness of the roughened cured product layer can be improved. For example, it becomes easy to make the entire roughened surface of the cured product a surface having a uniform roughness with an arithmetic average roughness Ra of 200 μm or less.

  The content of the cyanate curing agent A in 100% by weight of the total resin component X is preferably 3% by weight or more, more preferably 5% by weight or more, preferably 50% by weight or less, more preferably 30% by weight or less. . When the content of the cyanate curing agent A is not less than the above lower limit and not more than the above upper limit, a better cured product can be obtained, and the dimensional change due to heat of the cured product can be further suppressed.

  The total content a of tetramethylbisphenol F type dicyanate and the polymer of the polymerization component containing the tetramethylbisphenol F type dicyanate is preferably 1% by weight or more in 100% by weight of the whole cyanate curing agent A. More preferably, it is 10 weight% or more and 100 weight% or less, More preferably, it is 90 weight% or less, Preferably it is 70 weight% or less. When the content a is equal to or more than the lower limit, the uniformity of the roughness of the roughened surface of the cured product is further increased. When the content a is not more than the above upper limit, the dimensional change due to heat of the cured product after curing is further reduced.

[Inorganic filler]
The epoxy resin material preferably contains an inorganic filler. The inorganic filler is not particularly limited. As the inorganic filler, a conventionally known inorganic filler can be used. As for the said inorganic filler, only 1 type may be used and 2 or more types may be used together.

  Examples of the inorganic filler include silica, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, aluminum nitride, and boron nitride. From the viewpoints of reducing the surface roughness of the surface of the cured product that has been roughened, forming finer wiring on the surface of the cured product, and imparting good insulation reliability to the cured product, the inorganic filling described above. The material is preferably silica or alumina, more preferably silica, and still more preferably fused silica. By using silica, the linear expansion coefficient of the cured product can be further reduced, and the surface roughness of the roughened cured product surface can be effectively reduced. The shape of silica is preferably substantially spherical.

  The average particle diameter of the inorganic filler is preferably 0.1 μm or more, preferably 20 μm or less, more preferably 1 μm or less. As the average particle diameter of the inorganic filler, a median diameter (d50) value of 50% is adopted. The average particle size can be measured using a laser diffraction / scattering particle size distribution measuring apparatus.

  The inorganic filler is preferably surface-treated, and more preferably surface-treated with a coupling agent. As a result, the surface roughness of the cured product that has been roughened can be further reduced, and finer wiring can be formed on the surface of the cured product. And interlayer insulation reliability can be imparted.

  Examples of the coupling agent include silane coupling agents, titanate coupling agents, and aluminum coupling agents. Examples of the silane coupling agent include amino silane, imidazole silane, and epoxy silane.

  The content of the inorganic filler is not particularly limited. The content of the inorganic filler is preferably 30% by weight or more, more preferably 40% in 100% by weight of the total solid content (hereinafter sometimes abbreviated as total solid content Y) contained in the epoxy resin material. % By weight or more, more preferably 50% by weight or more, preferably 85% by weight or less, more preferably 80% by weight or less. When the content of the inorganic filler is not less than the above lower limit and not more than the above upper limit, the surface roughness of the roughened cured product can be further reduced, and the surface of the cured product is finer. Wiring can be formed. “Total solid content Y” refers to the total of the epoxy resin, the curing agent, the inorganic filler, and the solid content blended as necessary. “Solid content” refers to a non-volatile component that does not volatilize during molding or heating.

  When the content of the inorganic filler in the total solid content Y is 50% by weight or more, the dimensional change due to heat of the cured product is further reduced.

[Thermoplastic resin]
The epoxy resin material according to the present invention preferably contains a thermoplastic resin. By using the thermoplastic resin, it is possible to improve the followability of the circuit of the epoxy resin material to the unevenness of the circuit, and it is possible to further reduce the surface roughness of the surface of the cured product that has been subjected to the roughening treatment. The roughness of the roughened surface can be made even more uniform.

  Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyimide resin, polycarbonate resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, and polyester resin. From the viewpoint of increasing the heat resistance of the cured product and improving the compatibility with the epoxy resin and cyanate curing agent A, the thermoplastic resin is preferably a phenoxy resin.

  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, and a naphthalene skeleton.

  When the surface of the cured product of the resin composition is roughened and then plated to form a metal layer, the adhesive strength between the cured product and the metal layer can be increased. It preferably has a skeleton, and more preferably has a biphenol skeleton.

  Specific examples of the phenoxy resin include, for example, “YP50”, “YP55” and “YP70” manufactured by Toto Kasei Co., Ltd., and “1256B40”, “4250”, “4256H40”, “4275” manufactured by Mitsubishi Chemical Corporation, “YX6954BH30”, “YX8100BH30”, “YL7600DMAcH25”, “YL7213BH30”, and the like.

  The weight average molecular weight of the phenoxy resin is preferably 5000 or more, and preferably 100,000 or less.

  The content of the thermoplastic resin is not particularly limited. The content of the thermoplastic resin in 100% by weight of the total resin component X is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, still more preferably 1% by weight or more, preferably 40% by weight. Hereinafter, it is more preferably 30% by weight or less, further preferably 20% by weight or less, and particularly preferably 15% by weight or less. When the content of the thermoplastic resin is not less than the above lower limit and not more than the above upper limit, adverse effects on dimensional changes due to heat of the cured product are reduced. Moreover, the embedding property with respect to the hole or unevenness | corrugation of the circuit board of an epoxy resin material becomes it favorable that content of the said thermoplastic resin is below the said upper limit. The total resin component X includes the thermoplastic resin.

[Details of other components and epoxy resin materials]
The said epoxy resin material may contain the hardening accelerator as needed. By using a curing accelerator, the curing rate can be further increased. By quickly curing the epoxy resin material, the dispersion state of the inorganic filler in the cured product becomes better, the dimensional change due to heat of the cured product becomes better, or the roughened surface of the cured product Uniformity can be improved. However, the epoxy material according to the present invention can be cured quickly without using a curing accelerator. The curing accelerator is not particularly limited, and a conventionally known curing accelerator can be used. As for the said hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Examples of the curing accelerator include imidazole compounds, phosphorus compounds, amine compounds, and organometallic compounds.

  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 ′ -Methyl Midazolyl- (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 Isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-dihydroxymethylimidazole Can be mentioned.

  Examples of the phosphorus compound include triphenylphosphine.

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

  Examples of the organic metal salt include zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), and trisacetylacetonate cobalt (III).

  From the viewpoint of increasing the insulation reliability of the cured product, the curing accelerator is particularly preferably an imidazole compound.

  The content of the curing accelerator is not particularly limited. From the viewpoint of efficiently curing the epoxy resin material, the content of the curing accelerator is 0% by weight or more, preferably 0.01% by weight or more, preferably 3% by weight or less in the total resin component X of 100% by weight. More preferably, it is 1% by weight or less. The total resin component X contains the curing accelerator.

  For the purpose of improving impact resistance, heat resistance, resin compatibility and workability, epoxy resin materials include coupling agents, colorants, antioxidants, UV degradation inhibitors, antifoaming agents, and thickeners. A thixotropic agent and other resins other than those mentioned above 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 vinyl silane, amino silane, imidazole silane, and epoxy silane.

  Examples of the other resin include polyphenylene ether resin, divinyl benzyl ether resin, polyarylate resin, diallyl phthalate resin, polyimide resin, benzoxazine resin, benzoxazole resin, bismaleimide resin, and acrylate resin.

(B-stage film epoxy resin material)
The epoxy resin material according to the present invention may be a resin composition or a B-stage film in which the resin composition is formed into a film.

  As a method for forming the resin composition into a film, for example, an extrusion molding method is used in which the resin composition is melt-kneaded using an extruder, extruded, and then formed into a film using a T-die or a circular die. Examples thereof include a casting molding method in which the resin composition is dissolved or dispersed in a solvent such as an organic solvent and then cast into a film, and other conventionally known film molding methods. Of these, the extrusion molding method or the casting molding method is preferable because the thickness can be reduced. The film includes a sheet.

  A B-stage film can be obtained by forming the resin composition into a film and drying it by heating at 90 to 200 ° C. for 10 to 180 minutes, for example, so that curing by heat does not proceed excessively.

  The film-like resin composition that can be obtained by the drying process as described above is referred to as a B-stage film.

  The B-stage film is a semi-cured product in a semi-cured state. The semi-cured product is not completely cured and curing can proceed further.

  The said resin composition can be used suitably in order to form a laminated film provided with a base material and the B stage film laminated | stacked on one surface of this base material. A B-stage film of a laminated film is formed from the resin composition.

  Examples of the base material 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, polyimide resin film, metal foil such as copper foil and aluminum foil, and the like. Can be mentioned. The surface of the base material may be subjected to a release treatment as necessary.

  When the epoxy resin material is used as an insulating layer of a circuit, the thickness of the layer formed of the epoxy resin material is preferably equal to or greater than the thickness of the conductor layer that forms the circuit. The thickness of the layer formed of the epoxy resin material is preferably 5 μm or more, and preferably 200 μm or less.

(Printed wiring board)
The said epoxy resin material is used suitably in order to form an insulating layer in a printed wiring board.

  The printed wiring board can be obtained, for example, by heat-pressing the B stage film using a B stage film formed of the resin composition.

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

(Copper-clad laminate and multilayer board)
The said epoxy resin material is used suitably in order to obtain a copper clad laminated board. An example of the copper-clad laminate is a copper-clad laminate comprising a copper foil and a B stage film laminated on one surface of the copper foil. The copper-clad laminate B-stage film is formed of the epoxy resin material according to the present invention.

  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 to 50 μm. Moreover, in order to raise the adhesive strength of the hardened | cured material layer which hardened the epoxy resin material, and copper foil, it is preferable that the said copper foil has a fine unevenness | corrugation on the surface. The method for forming the unevenness is not particularly limited. Examples of the method for forming the unevenness include a formation method by treatment using a known chemical solution.

  Moreover, the epoxy resin material according to the present invention is suitably used for obtaining a multilayer substrate. As an example of the multilayer substrate, there is a circuit substrate including a circuit substrate and a cured product layer laminated on the surface of the circuit substrate. The cured product layer of the multilayer substrate is formed by curing the epoxy resin material. It is preferable that the said hardened | cured material layer is laminated | stacked on the surface in which the circuit of the circuit board was provided. Part of the cured product layer is preferably embedded between the circuits.

  In the multilayer substrate, the surface of the cured product layer opposite to the surface on which the circuit substrate is laminated is preferably roughened or desmeared, and more preferably roughened.

  The roughening method can be any conventionally known roughening method and is not particularly limited. The surface of the cured product layer may be swelled before the roughening treatment.

  Moreover, it is preferable that the said multilayer substrate is further equipped with the copper plating layer laminated | stacked on the surface by which the roughening process of the said hardened | cured material layer was carried out.

  Further, as another example of the multilayer board, a circuit board, a cured product layer laminated on the surface of the circuit board, and a surface of the cured product layer opposite to the surface on which the circuit board is laminated are provided. A circuit board provided with the laminated copper foil is mentioned. The cured product layer and the copper foil are formed by curing the B-stage film using a copper-clad laminate comprising a copper foil and a B-stage film laminated on one surface of the copper foil. Preferably it is. Furthermore, it is preferable that the copper foil is etched and is a copper circuit.

  Another example of the multilayer board is a circuit board including a circuit board and a plurality of cured product layers stacked on the surface of the circuit board. At least one of the plurality of cured product layers is formed by curing the epoxy resin material. It is preferable that the multilayer substrate further includes a circuit laminated on at least one surface of the cured product layer formed by curing the epoxy resin material.

  FIG. 1 is a partially cutaway front sectional view schematically showing a multilayer substrate using an epoxy resin material according to an embodiment of the present invention.

  In the multilayer substrate 11 shown in FIG. 1, a plurality of cured product layers 13 to 16 are laminated on the upper surface 12 a of the circuit substrate 12. The cured product layers 13 to 16 are insulating layers. A metal layer 17 is formed in a partial region of the upper surface 12 a of the circuit board 12. Among the plurality of cured product layers 13 to 16, the cured product layers 13 to 15 other than the cured product layer 16 located on the outer surface opposite to the circuit board 12 side include a metal layer in a partial region of the upper surface. 17 is formed. The metal layer 17 is a circuit. Metal layers 17 are respectively arranged between the circuit board 12 and the cured product layer 13 and between the laminated cured product layers 13 to 16. 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 substrate 11, the cured product layers 13 to 16 are formed by curing the epoxy resin material according to the present invention. In this embodiment, since the surfaces of the cured product layers 13 to 16 are roughened or desmeared, fine holes (not shown) are formed on the surfaces of the cured product layers 13 to 16. Further, the metal layer 17 reaches the inside of the fine hole. Moreover, in the multilayer substrate 11, the width direction dimension (L) of the metal layer 17 and the width direction dimension (S) of the part in which the metal layer 17 is not formed can be made small. In the multilayer substrate 11, good insulation reliability is imparted between the upper metal layer 17 and the lower metal layer 17 that are not connected by via-hole connection and through-hole connection (not shown).

(Roughening treatment and swelling treatment)
The epoxy resin material according to the present invention is preferably used in order to obtain a cured product that is roughened or desmeared. The cured product includes a precured product that can be further cured.

  In order to form fine irregularities on the surface of the precured material obtained by precuring the epoxy resin material according to the present invention, the precured material is preferably subjected to a roughening treatment. Prior to the roughening treatment, the precured product is preferably subjected to a swelling treatment. The cured product is preferably subjected to a swelling treatment after preliminary curing and before the roughening treatment, and is further cured after the roughening treatment. However, the pre-cured product may not necessarily be subjected to the swelling treatment.

  As a method for the swelling treatment, for example, a method of treating a precured product with an aqueous solution or an organic solvent dispersion solution of a compound mainly composed of ethylene glycol 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 a precured product with a 40 wt% ethylene glycol aqueous solution at a treatment temperature of 30 to 85 ° C. for 1 to 30 minutes. The swelling treatment temperature is preferably in the range of 50 to 85 ° C. When the temperature of the swelling treatment is too low, it takes a long time for the swelling treatment, and the roughened adhesive strength between the cured product and the metal layer tends to be low.

  For the roughening treatment, for example, a chemical oxidizing agent such as a manganese compound, a chromium compound, or a persulfuric acid compound is used. These chemical oxidizers are used as an aqueous solution or an organic solvent dispersion after water or an organic solvent is added. The roughening liquid used for the roughening treatment generally contains an alkali as a pH adjuster or the like. The roughening solution 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 method for the roughening treatment is not particularly limited. As a method of the said roughening process, 30-90 g / L permanganic acid or a permanganate solution and 30-90 g / L sodium hydroxide solution are used, for example, process temperature 30-85 degreeC and 1-30 minutes. A method of treating a precured product once or twice under conditions is preferable. It is preferable that the temperature of the said roughening process exists in the range of 50-85 degreeC.

  The arithmetic average roughness Ra of the surface of the roughened cured product is 50 nm or more and 350 nm or less, and more preferably 200 nm or less. In this case, the adhesive strength between the cured product and the metal layer or wiring can be increased, and further finer wiring can be formed on the surface of the cured product layer.

(Desmear treatment)
Moreover, a through-hole may be formed in the precured material or hardened | cured material obtained by precuring the epoxy resin material which concerns on this invention. In the multilayer substrate or the like, a via or a through hole is formed as a through hole. For example, the via can be formed by irradiation with a laser such as a CO ₂ laser. The diameter of the via is not particularly limited, but is about 60 to 80 μm. Due to the formation of the through hole, a smear that is a resin residue derived from the resin component contained in the cured product layer is often formed at the bottom of the via.

  In order to remove the smear, the surface of the cured product layer is preferably desmeared. The desmear process may also serve as a roughening process.

  In the desmear treatment, for example, a chemical oxidant such as a manganese compound, a chromium compound, or a persulfate compound is used in the same manner as the roughening treatment. These chemical oxidizers are used as an aqueous solution or an organic solvent dispersion after water or an organic solvent is added. The desmear treatment liquid used for the desmear treatment generally contains an alkali. The desmear treatment liquid preferably contains sodium hydroxide.

  The method for the desmear treatment is not particularly limited. As a method for the desmear treatment, for example, using a 30 to 90 g / L permanganate or permanganate solution and a 30 to 90 g / L sodium hydroxide solution, a treatment temperature of 30 to 85 ° C. and a condition of 1 to 30 minutes A method of treating a precured product or a cured product once or twice is preferable. It is preferable that the temperature of the said desmear process exists in the range of 50-85 degreeC.

  By using the epoxy resin material according to the present invention, the surface roughness of the surface of the cured product subjected to the desmear treatment can be sufficiently reduced.

  Hereinafter, the present invention will be specifically described by giving examples and comparative examples. The present invention is not limited to the following examples.

  In the examples and comparative examples, the following materials were used.

(Epoxy resin)
Bisphenol A type epoxy resin (“850” manufactured by DIC) Biphenyl type epoxy resin (“NC-3000-H” manufactured by Nippon Kayaku Co., Ltd.)

(Cyanate curing agent)
Cyanate curing agent 1 (tetramethylbisphenol F-type dicyanate-containing cyanate ester resin, 10% by weight of tetramethylbisphenol F-type dicyanate represented by the above formula (1A), and the weight of the polymerization component containing the tetramethylbisphenol F-type dicyanate "BA-3000S" manufactured by Lonza Japan Co., which contains 59% by weight of the coalescence, 75% by weight of solids and 25% by weight of methyl ethyl ketone)
Cyanate curing agent 2 ("BA-230S" manufactured by Lonza Japan, including solid content 75% by weight and methyl ethyl ketone 25% by weight)

(Curing accelerator)
Imidazole compound (2-phenyl-4-methylimidazole, “2P4MZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.)

(Thermoplastic resin)
Phenoxy resin ("YX6954BH30" manufactured by Mitsubishi Chemical Corporation, containing 30 wt% solids, 35 wt% methyl ethyl ketone, and 35 wt% cyclohexanone)

(Inorganic filler)
Silica-containing slurry (manufactured by Admatechs "SC2050-HND", average particle size 0.5 µm, solid content 70 wt% and cyclohexanone 30 wt%)

Example 1
4.2 parts by weight of cyanate curing agent 1 (“BA-3000S” manufactured by Lonza Japan), 3.0 parts by weight of cyanate curing agent 2 (“BA-230S” manufactured by Lonza Japan), and bisphenol A type epoxy resin ( DIC (“850”) 8.6 parts by weight, biphenyl type epoxy resin (Nippon Kayaku “NC-3000-H”) 7.1 parts by weight, and phenoxy resin (Mitsubishi Chemical Corporation “YX6954BH30”) 12.6 parts by weight, 64.1 parts by weight of silica-containing slurry (“SC2050-HND” manufactured by Admatechs) and 0.4 part by weight of an imidazole compound (“2P4MZ” manufactured by Shikoku Kasei Co., Ltd.) are mixed uniformly. The solution was stirred at room temperature until a fresh solution was obtained to obtain a varnish.

  The varnish was coated on the release treatment surface of the PET film (“XG284” manufactured by Toray Industries Inc., thickness 25 μm) using a coating machine. The solvent was volatilized by drying in a gear oven at 100 ° C. for 10 minutes. In this way, a sheet-like molded body having a thickness of 40 μm and a solvent remaining amount of 1.0 wt% or more and 1.5 wt% or less was obtained on the PET film.

(Examples 2-5 and Comparative Examples 1-2)
The remaining amount of the solvent was 1.0% by weight or more and 1.5% by weight in the same manner as in Example 1 except that the type and blending amount (parts by weight) of the materials used were changed as shown in Table 1 below. A sheet-like molded body having a percentage of not more than% was produced.

(Evaluation)
(A) Production of Laminate Etching is performed on both sides of a glass cloth base epoxy resin double-sided copper-clad laminate (“E-679F” manufactured by Hitachi Chemical Co., Ltd., thickness 0.6 mm) with “CZ8101” manufactured by MEC, An etched laminate was obtained. Next, the obtained sheet-like molded body was laminated on both surfaces of the laminated board by a vacuum laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.). The vacuum lamination was performed under the conditions of vacuum 20 seconds, 70 ° C., 0.5 MPa, and the press was performed under the conditions of pressure 115 ° C., 1.0 MPa, 40 seconds. It should be noted that lamination was performed under the same conditions when vacuum laminating described later. Thereafter, the PET film was peeled off, and the sheet-like molded body was precured (semi-cured) at 170 ° C. for 60 minutes, to obtain a laminate A-1 having a semi-cured precured product.

  Further, in order to verify the roughening unevenness, the obtained sheet-like molded body was vacuum-laminated (the above-mentioned conditions) on both surfaces of a glass epoxy substrate (“CS-3665” manufactured by Risho Kogyo Co., Ltd.). Thereafter, the PET film was peeled off, and a sheet-like molded body was precured (semi-cured) at 170 ° C. for 60 minutes to obtain a laminate A-2 having a semi-cured precured product.

(B) Swelling treatment The obtained laminate A-1 was placed in a 60 ° C. swelling liquid (Swelling Dip Securigant P, manufactured by Atotech Japan) and rocked for 15 minutes. Thereafter, it was washed with pure water. The same process was performed also about laminated body A-2.

(C) Permanganate treatment (roughening treatment)
The swollen laminate A-1 was placed in a 80 ° C. potassium permanganate (Concentrate Compact CP, manufactured by Atotech Japan) roughening aqueous solution and rocked for 25 minutes. Then, it wash | cleaned for 2 minutes with the washing | cleaning liquid (Reduction securigant P, the Atotech Japan company make) of 25 degreeC, and also wash | cleaned further with the pure water. A layered product B-1 in which the surface of the precured product was roughened was obtained. The same process was performed on the swelled laminate A-2 to obtain a laminate B-2 whose surface was roughened. About the obtained laminated body B-1 and laminated body B-2, arithmetic mean roughness Ra of the roughened surface was measured.

(D) Plating process About the obtained laminated body B-1, the electroless copper plating and the electrolytic copper plating process were performed in the following procedures.

  The surface of the obtained laminate B-1 was treated with an alkaline cleaner (cleaner securigant 902) at 55 ° C. for 5 minutes and degreased and washed. After washing, the roughened pre-cured product was treated with a 23 ° C. pre-dip solution (Pre-Dip Neogant B) for 2 minutes. Next, it was treated with an activator solution (activator Neogant 834) at 40 ° C. for 5 minutes to attach a palladium catalyst. Then, it processed for 5 minutes with the reducing liquid (reducer neogant WA) of 30 degreeC.

  Next, the pre-cured product was put in a chemical copper solution (basic print gantt MSK-DK, copper print gantt MSK, stabilizer print gantt MSK), and electroless plating was performed until the plating thickness reached about 0.5 μm. After the electroless plating, annealing was performed at a temperature of 120 ° C. for 30 minutes in order to remove the remaining hydrogen gas. All the steps up to the electroless plating step were performed while the pre-cured product was swung with a processing solution of 1 L on a beaker scale.

  Next, electroplating was performed on the precured material that had been subjected to electroless plating until the plating thickness reached 25 μm. Using copper sulfate (reducer Cu) as the electrolytic copper plating, a current of 0.6 A / cm 2 was passed. After the copper plating treatment, the precured product was cured by heating at 190 ° C. for 90 minutes to obtain a laminate C-1 having a copper plating layer formed thereon. The same process was performed about laminated body B-2, and laminated body C-2 in which the copper plating layer was formed was obtained. About the obtained laminated body C-1 and laminated body C-2, the peeling strength of the copper plating layer was measured.

<Evaluation of thermal expansion coefficient>
The obtained sheet-like molded body was cured on a PET film at 170 ° C. for 30 minutes, and further cured at 190 ° C. for 90 minutes to obtain a cured body. The obtained cured body was cut into a size of 3 mm × 25 mm. Using a linear expansion meter (“TMA / SS120C” manufactured by Seiko Instruments Inc.), 25 to 150 of the cured product cut under the conditions of a tensile load of 3.3 × 10 ⁻² N and a heating rate of 5 ° C./min. The average coefficient of linear expansion at 0 ° C. was measured. The thermal expansion coefficient was determined according to the following criteria.

[Criteria for thermal expansion coefficient]
○: Average linear expansion coefficient is 30 ppm / ° C. or less Δ: Average linear expansion coefficient exceeds 30 ppm / ° C., 40 ppm / ° C. or less ×: Average linear expansion coefficient exceeds 40 ppm / ° C.

<Measurement of arithmetic average roughness Ra>
Using a non-contact type surface roughness meter (trade name “WYKO”, manufactured by Beiko Co., Ltd.), the arithmetic average roughness Ra of the roughened surface of the laminate B-1 and the laminate B-2 was determined. It was measured. Arithmetic mean roughness Ra conformed to JIS B 0601-1994.

[Criteria for arithmetic mean roughness Ra]
○: Arithmetic average roughness Ra is 200 nm or less Δ: Arithmetic average roughness Ra exceeds 200 nm, 300 nm or less ×: Arithmetic average roughness Ra exceeds 300 nm

<Uniformity of rough surface (roughness)>
The arithmetic average roughness of the roughened surface of the preliminary-cured product portion provided in the laminate B-1 and the roughened surface of the preliminary-cured product portion provided in the laminate B-2 From the measurement results of Ra, the uniformity of roughness was determined according to the following criteria.

[Roughness uniformity criteria]
○: Arithmetic average between the roughened surface of the precured product portion provided in the laminate B-1 and the roughened surface of the precured product portion provided in the laminate B-2 Absolute value of difference in roughness Ra (nm) is 50 nm or less. Δ: Roughened surface of pre-cured product provided in laminate B-1 and pre-cured in laminate B-2 The absolute value of the difference in arithmetic average roughness Ra (nm) exceeds 50 nm and 100 nm or less between the roughened surface of the product part and X: the roughness of the precured product part provided in the laminate B-1 The absolute value of the difference in arithmetic average roughness Ra (nm) exceeds 100 nm between the surface subjected to the chemical treatment and the surface subjected to the roughening treatment of the precured product portion provided in the laminate B-2

<Measurement of peel strength>
Cutouts were made in a width of 10 mm on the surfaces of the copper plating layers of the laminate C-1 and the laminate C-2 on which the copper plating layer was formed. Then, using a tensile tester (trade name “Autograph”, manufactured by Shimadzu Corporation), a copper plating layer and a cured product layer provided on the cured product layer at a crosshead speed of 5 mm / min. The adhesive strength was measured, and the obtained measured value was defined as peel strength.

[Peel strength criteria]
○: Peel strength is 5.9 N / cm or more ×: Peel strength is less than 5.9 N / cm

<Evaluation of storage stability>
Using a viscoelasticity measuring device (“AR2000ex” manufactured by TA Instruments Japan Co., Ltd.), the viscosity η * at 100 ° C. of the obtained sheet-like molded body was measured. Next, the sheet-like molded body was left at 24 ° C. for 48 hours. The viscosity η * at 100 ° C. of the sheet-like molded product after being left standing was measured. From the measured value of the obtained viscosity η *, the storage stability was determined according to the following criteria.

[Criteria for storage stability]
○: Change in viscosity η * of the molded product after standing is 10% or less with respect to the viscosity η * of the molded product before standing X: Molded product after standing with respect to the viscosity η * of the molded product before standing Change in viscosity η * of the product exceeds 10%

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Circuit board 1a ... Upper surface 2 ... Metal layer 3 ... Hardened | cured material layer 3A ... Hardened | cured material layer located in the part in which the metal layer is provided 3B ... Hardened | cured material layer 3a located in the part in which the metal layer is not provided 3a ... Surface 11 ... Multilayer substrate 12 ... Circuit board 12a ... Upper surface 13-16 ... Hardened material layer 17 ... Metal layer (wiring)

Claims (9)

A B-stage film used for forming a cured product layer on both the portion with the metal layer and the portion without the metal layer on the surface of the circuit board on which the metal layer is partially provided on the upper surface,
It is a B stage film formed into a film,
Containing an epoxy resin, a curing agent, and an inorganic filler,
The curing agent includes a cyanate curing agent including at least one of tetramethylbisphenol F type dicyanate and a polymer of a polymerization component including the tetramethylbisphenol F type dicyanate;
In a total of 100% by weight of all resin components in the B-stage film , the content of the cyanate curing agent is 5% by weight or more and 30% by weight or less,
Entire solid content 100 wt% in B stage film state, and are the content of the inorganic filler is 30 wt% or more,
The total content of the tetramethyl bisphenol F type dicyanate and the polymer of the polymerization component containing the tetramethyl bisphenol F type dicyanate is 1% by weight or more and 70% by weight or less in 100% by weight of the whole cyanate curing agent. Oh Ru, B stage film. Entire solid content 100 wt% in B stage film, the content of the inorganic filler is 40 wt% or more and 80 wt% or less, B-stage film according to claim 1. The B stage film according to claim 1 or 2 , wherein the inorganic filler is silica. The B stage film according to any one of claims 1 to 3 , further comprising a thermoplastic resin. The B stage film according to claim 4 , wherein the content of the thermoplastic resin is 1% by weight or more and 30% by weight or less in a total of 100% by weight of all resin components in the B stage film . The B-stage film according to claim 4 or 5 , wherein the thermoplastic resin is a phenoxy resin. Contains or does not contain a curing accelerator,
When a hardening accelerator is contained, content of the said hardening accelerator is 1 weight% or less in the total of 100 weight% of all the resin components in a B stage film , Any one of Claims 1-6 B stage film as described in the item. A B-stage film to be used for obtaining a roughening treatment or desmearing cured product is, B-stage film according to any one of claims 1-7. A circuit board with a metal layer partially provided on the upper surface ;
Oite on the surface of the circuit board, and a cured layer disposed on both the part and the metal layer is not part there is a metal layer,
The multilayer substrate in which the said hardened | cured material layer is formed by hardening the B stage film of any one of Claims 1-8 .

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