JP5508342B2 - B-stage film for printed wiring board and multilayer board - Google Patents

Description

  The present invention relates to an epoxy resin material used for forming an insulating layer of a multilayer substrate, for example, and more specifically, an epoxy resin material containing an epoxy resin and a curing agent, and a multilayer substrate using the epoxy resin material About.

  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, Patent Document 1 below discloses a resin composition containing a cyanate resin, a phenol resin, and an inorganic filler. Here, it is described that the flame retardancy and heat resistance of the resin composition are high and the coefficient of linear expansion is low. Patent Document 1 describes that it is preferable to use an epoxy resin in order to improve the reactivity of the cyanate resin.

  Patent Document 2 below discloses a resin composition containing a cyanate ester resin, an anthracene epoxy resin, and a thermoplastic resin such as a phenoxy resin. Here, it is described that the thermal expansion coefficient of the resin composition is low and that an insulating layer in which smear can be easily removed can be formed.

JP 2003-096296 A JP 2007-291368 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 significantly reduce the linear expansion coefficient of the insulating layer stacked on the substrate.

  However, when conventional resin compositions as described in Patent Documents 1 and 2 are used, the dimensional change due to heat of the cured product of the resin composition may not be sufficiently reduced, and the insulation The linear expansion coefficient of the layer may be relatively high.

  Furthermore, in the conventional resin composition, the heat resistance of the cured product may be low. Therefore, there exists a problem that the heat resistance reliability of the multilayer printed wiring board which has the insulating layer formed with the conventional resin composition becomes low.

  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 heat resistance of the cured product, and a multilayer substrate using the epoxy resin material It is to be.

  A limited object of the present invention is to provide an epoxy resin material that can improve the laminating property (embedding property) even when a large amount of filler such as silica is blended, and a multilayer substrate using the epoxy resin material. is there.

  According to a wide aspect of the present invention, there is provided an epoxy resin material comprising an epoxy resin represented by the following formula (1) and a curing agent having two or more functional groups capable of reacting with the epoxy group of the epoxy resin. Is done.

  In said formula (1), X represents a carbonyl group or a sulfonyl group.

  The epoxy resin represented by the above formula (1) is preferably an epoxy resin represented by the following formula (1A). X in the above formula (1) and X in the following formula (1A) are each preferably a sulfonyl group.

  In the above formula (1A), X represents a carbonyl group or a sulfonyl group.

  The curing agent is preferably a curing agent having an aminotriazine skeleton. The curing agent is preferably a cresol novolak curing agent having an aminotriazine skeleton or a phenol novolac curing agent having an aminotriazine skeleton.

  In a specific aspect of the epoxy resin material according to the present invention, silica is further included.

  The epoxy resin material according to the present invention is preferably a B-stage film formed into a film.

  The epoxy resin material according to the present invention is preferably an epoxy resin material used for obtaining a cured product that is roughened or desmeared.

  The multilayer substrate 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 is formed by curing the epoxy resin material configured according to the present invention. Has been.

  Since the epoxy resin material according to the present invention includes an epoxy resin represented by the formula (1) and a curing agent having two or more functional groups capable of reacting with the epoxy group of the epoxy resin, a cured product after curing. The dimensional change due to heat can be reduced, and the heat resistance 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.

  Details of the present invention will be described below.

(Epoxy resin material)
The epoxy resin material which concerns on this invention contains the epoxy resin represented by Formula (1), and the hardening | curing agent which has two or more functional groups which can react with the epoxy group of this epoxy resin.

  By adopting the above composition, it becomes possible to obtain a cured product having a small dimensional change due to heat. Furthermore, the heat resistance of hardened | cured material can also be improved by employ | adopting the said composition.

  The epoxy resin material according to the present invention preferably includes a filler, more preferably includes an inorganic filler, and further preferably includes silica. In the epoxy resin material containing the specific epoxy resin and the specific curing agent, the dimensional change due to heat of the cured product can be further reduced by adding a large amount of filler such as silica, that is, linear expansion. The rate can be lowered.

  Further, in the epoxy resin material according to the present invention, when the content of the filler is 100 parts by weight or more with respect to a total of 100 parts by weight of the epoxy resin and the curing agent, a dimensional change due to heat of the cured product. Becomes even smaller, that is, the linear expansion coefficient becomes lower. For example, it becomes even easier to set the average linear expansion coefficient of the cured product at 0 to 50 ° C. to 25 ppm / ° C. or less. As a result, even if the cured product is exposed to a high temperature in a reflow process or the like, the size of the cured product is not easily changed, and peeling of other cured products or circuits laminated on the cured product is difficult to occur. In the epoxy resin material according to the present invention, since the size of the cured product is not easily changed, the warpage of the substrate used in the package can be sufficiently suppressed in recent high-density packages.

  From the viewpoint of further reducing the dimensional change due to heat of the cured product and further suppressing peeling of the cured product, the average linear expansion coefficient at 0 to 50 ° C. of the cured product of the resin composition according to the present invention is: It is preferably 17 ppm / ° C. or less, which is the same as that of copper.

  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. The epoxy resin material according to the present invention is preferably a B-stage film formed into a film.

  Moreover, it is preferable that the epoxy resin material which concerns on this invention is an epoxy resin material used in order to obtain the hardened | cured material by which a roughening process or a desmear process is carried out.

  Hereinafter, details of the epoxy resin and the curing agent contained in the epoxy resin material according to the present invention, and the filler preferably contained will be described.

[Epoxy resin]
The epoxy resin contained in the epoxy resin material according to the present invention is an epoxy resin represented by the following formula (1). In the following formula (1), the binding site of the amino group having two diglycidylamino groups to the benzene ring is not particularly limited. Even if the amino group having two diglycidylamino groups in the following formula (1) is bonded to any part of the benzene ring, the dimensional change due to heat of the cured product is sufficiently small, and the heat resistance is sufficiently high.

  In said formula (1), X represents a carbonyl group or a sulfonyl group. A carbonyl group is a C═O group. A sulfonyl group is an O = S = O group.

  The epoxy resin has two diglycidyl diamino groups and four epoxy groups. Since the said epoxy resin has four epoxy groups, it can raise the crosslinking density of hardened | cured material. The epoxy resin has a highly polar carbonyl group or sulfonyl group. Since the epoxy resin has a plurality of diglycidyldiamino groups containing a plurality of epoxy groups and a carbonyl group or a sulfonyl group, the dimensional change due to heat of the cured product can be effectively reduced. Furthermore, it originates in the group mentioned above of the epoxy resin, and can also improve the heat resistance of hardened | cured material.

  Since carbonyl groups and sulfonyl groups are highly polar, resins can be easily packed together and have a stack structure, intermolecular forces such as hydrogen bonds are likely to work. For this reason, a carbonyl group and a sulfonyl group contribute to reducing the dimensional change by the heat | fever of hardened | cured material. Furthermore, since an epoxy resin having a carbonyl group or a sulfonyl group has a rigid structure, the glass transition temperature of the cured product is increased, and the dimensional change due to heat of the cured product is decreased.

  Moreover, generally the heat resistance of the cured | curing material of the epoxy resin material containing a diglycidyl amine type epoxy resin tends to become low. However, the heat resistance of a cured product of an epoxy resin material containing a diglycidylamine type epoxy resin having a carbonyl group or a sulfonyl group is an epoxy resin material containing a diglycidylamine type epoxy resin having no carbonyl group or a sulfonyl group. It becomes higher than the heat resistance of the cured product. Therefore, both good heat resistance and good dimensional stability can be realized by using an epoxy resin material containing a diglycidylamine type epoxy resin having a carbonyl group or a sulfonyl group.

  Specifically, the epoxy resin represented by the above formula (1) is any one of the epoxy resins represented by the following formulas (1A) to (1F).

  In the above formula (1A), X represents a carbonyl group or a sulfonyl group.

  In the above formula (1B), X represents a carbonyl group or a sulfonyl group.

  In the above formula (1C), X represents a carbonyl group or a sulfonyl group.

  In the above formula (1D), X represents a carbonyl group or a sulfonyl group.

  In the above formula (1E), X represents a carbonyl group or a sulfonyl group.

  In the above formula (1F), X represents a carbonyl group or a sulfonyl group.

  From the viewpoint of further reducing the dimensional change due to heat of the cured product and further improving the heat resistance of the cured product, the epoxy resin is represented by the above formula (1A), the above formula (1B), or the above formula (1D). It is preferably an epoxy resin represented, and more preferably an epoxy resin represented by the above formula (1A). For example, the epoxy resin represented by the above formula (1A), the above (1B), or the above formula (1D) has less steric hindrance and is easily cross-linked than the epoxy resin represented by the above formula (1C). Moreover, since the epoxy resin represented by the above formula (1A) has high solubility in a solvent, the handling property at the time of production is good, and by using the epoxy resin represented by the above formula (1A), heat of the cured product can be obtained. The dimensional change due to is considerably reduced, and the heat resistance of the cured product is considerably increased.

  X in the above formula (1) and the above formulas (1A) to (1F) is preferably a sulfonyl group. When X is not a carbonyl group but a sulfonyl group, the dimensional change due to heat of the cured product can be further reduced, and the heat resistance of the cured product can be further enhanced.

[Curing agent]
The hardening | curing agent contained in the epoxy resin material which concerns on this invention will not be specifically limited if it has two or more functional groups which can react with the epoxy group of the said epoxy resin. A conventionally known curing agent can be used as the curing agent. As for the said hardening | curing agent, only 1 type may be used and 2 or more types may be used together.

  Examples of the functional group capable of reacting with the epoxy group of the epoxy resin in the curing agent include a phenol group, an amino group, a cyanate ester group, and an acid anhydride group.

  Specific examples of the curing agent include a cyanate ester resin (cyanate ester curing agent), a phenol compound (phenol curing agent), an amine compound, an acid anhydride, and dicyandiamide. Especially, from a viewpoint of obtaining the hardened | cured material in which the dimensional change by a heat | fever is still smaller, it is preferable that the said hardening | curing agent is cyanate ester resin or a phenol compound. The curing agent is preferably a cyanate ester resin, and is preferably a phenol compound.

  From the viewpoint of further reducing the dimensional change due to heat of the cured product and further improving the heat resistance of the cured product, the curing agent preferably has an aminotriazine skeleton. Furthermore, from the viewpoint of further reducing the dimensional change due to heat of the cured product and further increasing the heat resistance of the cured product, the curing agent has a cresol novolac curing agent having an aminotriazine skeleton, or an aminotriazine skeleton. A phenol novolac curing agent is preferred.

  Even if polyfunctional phenol is used as the curing agent, the dimensional change due to heat of the cured product can be reduced, but the polyfunctional phenol curing agent having a specific epoxy resin and triazine structure represented by the above formula (1) In combination, the dimensional change due to heat of the cured product can be considerably reduced.

  Content of the said epoxy resin and the said hardening | curing agent is not specifically limited. The blending ratio of the epoxy resin and the curing agent is appropriately determined depending on the types of the epoxy resin and the curing agent.

[filler]
From the viewpoint of further reducing the dimensional change due to heat of the cured product, the epoxy resin material preferably contains a filler. Moreover, the surface roughness of the hardened | cured material by which the roughening process or the desmear process was carried out can be made small by use of a filler. As said filler, an inorganic filler, an organic filler, an organic inorganic composite filler, etc. are mentioned. Of these, inorganic fillers are preferred. As for the said filler, only 1 type may be used and 2 or more types may be used together.

  The inorganic filler is not particularly limited. As the inorganic filler, conventionally known inorganic fillers can be used. Examples of the inorganic filler include silica, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, aluminum nitride, and boron nitride. From the viewpoint of reducing the surface roughness of the roughened or desmeared precured product, forming finer wiring on the surface of the cured product, and imparting better insulation reliability to the cured product, The inorganic filler 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 lowered, and the surface roughness of the surface of the cured product subjected to the roughening treatment or desmear treatment can be effectively reduced. The shape of silica is preferably substantially spherical.

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

  The filler is preferably surface-treated, and more preferably surface-treated with a coupling agent. As a result, the surface roughness of the cured product subjected to the roughening treatment or the desmear treatment can be further reduced, and a finer wiring can be formed on the surface of the cured product, and the cured product has a better wiring. Interlayer insulation reliability 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 filler is preferably 100 parts by weight or more and preferably 900 parts by weight or less with respect to a total of 100 parts by weight of the epoxy resin and the curing agent. When the content of the filler is within the above range, a cured product having sufficiently small dimensional stability due to heat can be obtained.

  From the viewpoint of further reducing the dimensional change due to heat of the cured product, the content of the filler is preferably 120 parts by weight or more, more preferably 100 parts by weight in total for the epoxy resin and the curing agent. Is 135 parts by weight or more, particularly preferably 150 parts by weight or more. By adopting the above composition in the present invention, even when the filler content is 100 parts by weight or more, or 150 parts by weight or more, the handling property at the time of production can be ensured and the laminating property (embedding to a substrate with a pattern) Property) can be improved.

[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 rapidly curing the epoxy resin material, the crosslinked structure of the cured product can be made uniform, the number of unreacted functional groups can be reduced, and as a result, the crosslinking density can be increased. 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 organometallic compound 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. From the viewpoint of enhancing the insulation reliability of the cured product, the curing accelerator preferably does not contain an organometallic 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 preferably 0.01 parts by weight or more, preferably 3 parts per 100 parts by weight in total of the epoxy resin and the curing agent. Less than parts by weight.

  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 resins include phenoxy resin, polyvinyl acetal resin, polyphenylene ether resin, divinyl benzyl ether resin, polyarylate resin, diallyl phthalate resin, polyimide resin, benzoxazine resin, benzoxazole resin, bismaleimide resin, and acrylate resin. Can be mentioned.

(B-stage film epoxy resin material)
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.

  In FIG. 1, the multilayer substrate using the epoxy resin material which concerns on one Embodiment of this invention is typically shown with a partial notch front sectional drawing.

  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 an upper metal layer and a lower metal layer 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.

  When the swelling treatment is performed using the swelling liquid and then the roughening treatment is performed using the roughening liquid, the arithmetic average roughness Ra of the surface of the roughened cured product may be 50 nm or more and 350 nm or less. preferable. 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)
(1) Diglycidylamine type bisphenol S type epoxy resin (corresponding to the epoxy resin represented by the above formula (1A), X in the above formula (1A) is a sulfonyl group, “TG3DAS” manufactured by Konishi Chemical Co., Ltd., weight average Molecular weight 1000 or less, epoxy equivalent 138)
(2) Bisphenol A type epoxy resin (“RE410S” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 178)
(3) Dicyclopentadiene skeleton-containing epoxy resin (manufactured by DIC "HP7200L", epoxy equivalent 250)
(4) Epoxy resin (“ADEKA RESIN EP-3900S” manufactured by ADEKA, epoxy equivalent 100)

(Curing agent)
(1) Phenol novolak curing agent 1 (“MEH7851-4H” manufactured by Meiwa Kasei Co., Ltd., phenol curing agent equivalent 241)
(2) Phenol novolak curing agent 2 (“H-4”, Meiwa Kasei Co., Ltd., phenol curing agent equivalent 105)
(3) Aminotriazine skeleton cresol novolac curing agent-containing liquid (a DIC "LA3018-50P", a weight average molecular weight of 1000 or less, a solid content of 50% by weight, and a propylene glycol monomethyl ether-containing solvent of 50% by weight Equivalent 151)

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

(filler)
Silica-containing slurry (“SC2050HNK” manufactured by Admatechs, fused silica having an average particle size of 0.5 μm, silica is surface-treated with an aminosilane coupling agent, and contains 70 wt% solids and 30 wt% cyclohexanone)

Example 1
63.2 parts by weight (44.2 parts by weight of solid content) of the above silica-containing slurry (admatechs "SC2050HNK") and aminotriazine skeleton cresol novolac curing agent-containing liquid (DIC "LA3018-50P") 14 .6 parts by weight (7.3 parts by weight in solid content), 22.0 parts by weight of diglycidylamine-type bisphenol S-type epoxy resin (“TG3DAS” manufactured by Konishi Chemical Co., Ltd.), and an imidazole compound (manufactured by Shikoku Kasei Kogyo “ 2P4MZ ”) and 0.2 parts by weight were mixed and stirred at room temperature until a uniform liquid was obtained, to obtain a resin composition varnish.

  A release-treated transparent polyethylene terephthalate (PET) film (“PET5011 550” manufactured by Lintec Corporation, thickness 50 μm) was prepared. The obtained resin composition varnish was applied onto the surface of the PET film subjected to the mold release treatment using an applicator so that the thickness after drying was 50 μm. Next, it was dried in a gear oven at 100 ° C. for 2 minutes to prepare a laminated film of an uncured resin sheet (B stage film) having a length of 200 mm × width of 200 mm × thickness of 50 μm and a polyethylene terephthalate film. Next, the polyethylene terephthalate film was peeled from the laminated film, and the uncured product of the resin sheet was heated in a gear oven at 190 ° C. for 60 minutes to produce a primary cured product of the resin sheet.

(Examples 2 to 5 and Comparative Examples 1 to 3)
A primary cured product of a laminated film and a resin sheet was produced in the same manner as in Example 1 except that the type and amount (parts by weight) of the materials used were changed as shown in Table 1 below.

(Evaluation)
(1) Average linear expansion coefficient The obtained resin sheet primary cured product was cured by heating at 190 ° C. for 3 hours to obtain a cured product A. The obtained cured product A was cut into a size of 3 mm × 25 mm. Using a linear expansion coefficient meter (“TMA / SS120C” manufactured by Seiko Instruments Inc.), a tensile load of 3.3 × 10 ⁻² N, and a heating rate of 5 ° C./min. The average linear expansion coefficient at ° C was measured. The case where the average linear expansion coefficient at 0 to 50 ° C. was 25 ppm / ° C. or less was determined as “◯”, and the case where the average linear expansion coefficient at 0 to 50 ° C. exceeded 25 ppm / ° C. was determined as “x”.

(2) Heat resistance The primary cured product of the obtained resin sheet was cured by heating at 190 ° C. for 3 hours to obtain a cured product A. The obtained cured product A was die-cut to a size of 5 mm in diameter, and five sheets were stacked. Using a differential heat and thermogravimetric simultaneous measurement device (“DTG-60” manufactured by SHIMADZU) and using five cured products A that were punched and stacked, the heating rate was 10 ° C./min, and the atmosphere gas Measurement was performed in a temperature range of 30 to 800 ° C. under the condition of 100 mL / min of air. When the weight of only the resin excluding the filler at 30 ° C. was 100% by weight, the temperature when the resin content decreased by 3% by weight during the measurement was determined as Td3, and that temperature was used as an index of heat resistance. The case where Td3 was 300 ° C. or higher was determined as “◯”, and the case where Td3 was lower than 300 ° C. was determined as “×”.

(3) Evaluation of laminating property (embeddability on uneven surface) and undulation A copper-clad laminate (a laminate of a 150 μm thick glass epoxy substrate and a 35 μm thick copper foil) was prepared. The copper foil was etched to produce 26 copper patterns having an L / S of 50 μm / 50 μm and a length of 1 cm to obtain an uneven substrate.

  An uncured product (thickness 40 μm) of the obtained resin sheet was overlapped on the uneven surface of the uneven substrate, and a vacuum pressure laminator machine (model number MVLP-500) manufactured by Meiki Seisakusho Co., Ltd. was used. Lamination was performed at a laminating temperature of 90 ° C. for 20 seconds, and further pressed at a pressing pressure of 0.8 MPa and a pressing temperature of 90 ° C. for 20 seconds. In this way, a laminate (A) in which an uncured resin sheet was laminated on the concavo-convex substrate was obtained.

  In the obtained laminate (A), an uncured product of the resin sheet was heated at 170 ° C. for 60 minutes and then heated at 190 ° C. for 180 minutes to obtain a cured product C.

  Regarding the embedding property, the unevenness of the upper surface was measured using WYKO manufactured by Veeco in the state of the laminate (A) in which the uncured material was laminated. A case where the unevenness was 0.3 μm or less was determined as “◯”, a case where the unevenness was more than 0.3 μm and less than 0.5 μm was determined as “Δ”, and a case where the unevenness exceeded 0.5 μm was determined as “x”. Specifically, the value of the unevenness means a maximum height difference portion among several concave and convex portions adjacent to the unevenness.

  Regarding the undulation evaluation, the unevenness of the upper surface was measured using WYKO manufactured by Veeco in the state of the cured product C. The maximum unevenness was the undulation value. The case where the maximum value of the unevenness is 1.5 μm or less is “◯”, the case where the maximum value of the unevenness is more than 1.5 μm and 2.0 μm or less is “△”, and the case where it is more than 2.0 μm is “×”. It was determined. Specifically, the maximum value of the unevenness means the maximum difference in height among several adjacent concave and convex portions of the unevenness.

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 11 ... Multilayer substrate 12 ... Circuit board 12a ... Upper surface 13-16 ... Hardened | cured material layer 17 ... Metal layer

Claims (6)

A B-stage film formed into a film used to form an insulating layer in a printed wiring board,
An epoxy resin represented by the following formula (1);
Look contains a curing agent having a functional group reactive with an epoxy group of the epoxy resin 2 or more,
A B-stage film for printed wiring boards , wherein the curing agent is a cresol novolac curing agent having an aminotriazine skeleton or a phenol novolac curing agent having an aminotriazine skeleton .

In the formula (1), X represents a carbonyl group or a sulfonyl group. The B stage film for printed wiring boards according to claim 1, wherein the epoxy resin represented by the formula (1) is an epoxy resin represented by the following formula (1A).

In the formula (1A), X represents a carbonyl group or a sulfonyl group. The B stage film for printed wiring boards according to claim 1 or 2, wherein X is a sulfonyl group. The B stage film for printed wiring boards according to any one of claims 1 to 3 , further comprising silica. A printed wiring board B stage film to be used for obtaining a roughening treatment or desmearing is the cured product is an insulating layer, a printed wiring board for the B-stage film according to any one of claims 1-4 . A circuit board which is a printed wiring board ;
A hardened material layer that is disposed on the surface of the circuit board and is an insulating layer ;
The multilayer substrate in which the said hardened | cured material layer is formed by hardening the B stage film for printed wiring boards of any one of Claims 1-5 .

Images