Resin material, cured product, and multilayer printed wiring board

Abstract

Provided is a resin material with which the dielectric constant of a cured product can be lowered and in which hollow inorganic particles are resistant to cracking even when subjected to ultrasonic treatment.　A resin material according to the present invention contains a thermosetting compound (A) and hollow inorganic particles (B), the root mean square height Rq of the outer surface of the hollow inorganic particles (B) being 2 nm or greater.

Description

Resin materials, cured products, and multilayer printed wiring boards

[0001] The present invention relates to a resin material containing a thermosetting compound, a cured product of the resin material, and a multilayer printed wiring board using the resin material.

[0002] Conventionally, various resin materials have been used to obtain electronic components such as semiconductor devices, laminates, and printed wiring boards. For example, in multilayer printed wiring boards, resin materials are used to form insulating layers for insulating between internal layers and to form insulating layers located on the surface. Wiring, which is generally metal, is laminated on the surface of the insulating layer. Furthermore, film-like resin materials (resin films) are sometimes used to form the insulating layers. The resin materials are used as insulating materials for multilayer printed wiring boards, including build-up films.

[0003] Patent Document 1 listed below discloses a resin composition containing (A) an epoxy resin, (B) a curing agent, (C) hollow silica, and (D) fused silica. In this resin composition, when the nonvolatile components in the resin composition are taken as 100% by mass, the content of (C) hollow silica is 5 to 22% by mass, and the total content of (C) hollow silica and (D) fused silica is 50 to 70% by mass.

[0004] Patent Document 2 listed below discloses a resin composition containing a thermosetting resin (A) and a filler (B), wherein the filler (B) contains hollow particles (b) that satisfy a specific formula and have an average particle size of 0.01 to 10 μm.

[0005] JP 2013-173841 A

[0006] Resin materials containing a thermosetting compound and hollow inorganic particles are known, as described in Patent Documents 1 and 2. By using hollow inorganic particles, the dielectric constant of the cured resin material can be lowered to some extent.

[0007] Incidentally, when manufacturing electronic components such as printed wiring boards, wiring may be formed by laminating a resin material onto a substrate or the like, heating, desmearing, or ultrasonic treatment. However, when using a conventional resin material containing hollow inorganic particles, the hollow inorganic particles may crack during these treatments. Among these treatments, the hollow inorganic particles are particularly susceptible to cracking during ultrasonic treatment. When the hollow inorganic particles crack, the chemical solution used to form the wiring penetrates into the cracked portion, increasing the amount of copper that penetrates, which can lead to short circuits between the wiring.

[0008] An object of the present invention is to provide a resin material that can reduce the dielectric constant of the cured product and that does not easily break hollow inorganic particles even when subjected to ultrasonic treatment. Another object of the present invention is to provide a cured product of the resin material. A further object of the present invention is to provide a multilayer printed wiring board using the resin material.

[0009] This specification discloses the following resin material, cured product, and multilayer printed wiring board.

[0010] Item 1. A resin material comprising a thermosetting compound (A) and hollow inorganic particles (B), wherein the root mean square height Rq of the outer surface of the hollow inorganic particles (B) is 2 nm or more.

[0011] Item 2. The resin material according to Item 1, wherein the hollow inorganic particles (B) are hollow silica particles.

[0012] Item 3. The resin material according to Item 1 or 2, wherein the thermosetting compound (A) includes a thermosetting compound having an epoxy group, a vinyl group, a styryl group, a benzoxazine group, a cyanate group, an allyl group, a methacryloyl group, an acryloyl group, or a maleimide group.

[0013] Item 4. The resin material according to any one of Items 1 to 3, wherein the thermosetting compound (A) includes a maleimide compound.

[0014] Item 5. The resin material according to any one of Items 1 to 4, further comprising solid inorganic particles (C).

[0015] Item 6. The resin material according to any one of Items 1 to 5, wherein the content of the hollow inorganic particles (B) is 60% by weight or less based on 100% by weight of components excluding the solvent in the resin material.

[0016] Item 7. The resin material according to any one of Items 1 to 6, wherein when the resin material is heated at 180°C for 30 minutes and then heated at 200°C for 60 minutes to obtain a cured product of the resin material, the resulting cured product has a dielectric constant of 2.5 or less at 10 GHz.

[0017] Item 8. The resin material according to any one of Items 1 to 7, which is a resin film.

[0018] Item 9. The resin material according to any one of Items 1 to 8, which is used to form an insulating layer in a multilayer printed wiring board.

[0019] Item 10. A cured product of a resin material, wherein the resin material is the resin material according to any one of Items 1 to 9.

[0020] Item 11. A multilayer printed wiring board comprising a circuit board, a plurality of insulating layers disposed on a surface of the circuit board, and a metal layer disposed between the plurality of insulating layers, wherein at least one of the plurality of insulating layers is a cured product of the resin material according to any one of Items 1 to 9.

[0021] The resin material according to the present invention comprises a thermosetting compound (A) and hollow inorganic particles (B), and the hollow inorganic particles (B) have an outer surface root mean square height Rq of 2 nm or more. Because the resin material according to the present invention has the above-described configuration, the dielectric constant of the cured product can be reduced, and the hollow inorganic particles are less likely to crack even when subjected to ultrasonic treatment.

[0022] Fig. 1 is a cross-sectional view schematically showing a multilayer printed wiring board using a resin material according to one embodiment of the present invention. Fig. 2 is an atomic force microscope photograph of hollow silica particles B1 used in the examples. Fig. 3 is a diagram for explaining a method for calculating the plating penetration amount evaluated in the examples.

[0023] The present invention will be described in detail below.

[0024] (Resin Material) The resin material according to the present invention contains a thermosetting compound (A) and hollow inorganic particles (B), and the root mean square height Rq of the outer surface of the hollow inorganic particles (B) is 2 nm or more.

[0025] The resin material according to the present invention has the above-mentioned configuration, so that the dielectric constant of the cured product can be reduced, and the hollow inorganic particles are less likely to break even when subjected to ultrasonic treatment.

[0026] In the resin material according to the present invention, the dielectric constant of the cured product can be maintained low before and after ultrasonic treatment.

[0027] In conventional resin materials containing hollow inorganic particles, the hollow inorganic particles are prone to cracking even when laminated. In contrast, in the resin material of the present invention, the hollow inorganic particles are less likely to crack even when laminated. Therefore, the resin material of the present invention can reduce the dielectric constant of the cured product even when used in a laminated state.

[0028] Furthermore, in the resin material according to the present invention, the hollow inorganic particles are less likely to crack, so that short circuits between wirings can be effectively prevented.

[0029] The resin material according to the present invention may be a resin composition or a resin film. The resin composition has fluidity. The resin composition may be in a paste form. The paste form includes a liquid form. The resin material according to the present invention is preferably a resin film because it is easy to handle.

[0030] The resin material according to the present invention is preferably a thermosetting resin material. When the resin material is a resin film, the resin film is preferably a thermosetting resin film.

[0031] In the following description, "100% by weight of components in the resin material excluding the solvent" means 100% by weight of components in the resin material excluding the solvent when the resin material contains a solvent, and means 100% by weight of the resin material when the resin material does not contain a solvent. "100% by weight of components in the resin material excluding hollow inorganic particles (B), solid inorganic particles (C), and solvent" means 100% by weight of components in the resin material excluding the hollow inorganic particles (B), solid inorganic particles (C), and solvent when the resin material contains hollow inorganic particles (B), solid inorganic particles (C), and solvent. "100% by weight of components in the resin material excluding hollow inorganic particles (B), solid inorganic particles (C), and solvent" means 100% by weight of components in the resin material excluding the hollow inorganic particles (B), solid inorganic particles (C), and solvent when the resin material contains hollow inorganic particles (B) and solvent but does not contain solid inorganic particles (C). "100% by weight of the components in the resin material excluding the hollow inorganic particles (B), the solid inorganic particles (C), and the solvent" means 100% by weight of the components in the resin material excluding the hollow inorganic particles (B) when the resin material contains hollow inorganic particles (B) but does not contain solid inorganic particles (C) or the solvent.

[0032] Hereinafter, details of each component used in the resin material according to the present invention and uses of the resin material according to the present invention will be described.

[0033] [Thermosetting Compound (A)] The resin material contains a thermosetting compound (A). As the thermosetting compound (A), a conventionally known thermosetting compound can be used. Only one type of thermosetting compound (A) may be used, or two or more types may be used in combination.

[0034] The thermosetting compound (A) preferably contains a thermosetting compound having an epoxy group, a vinyl group, a styryl group, a benzoxazine group, a cyanate group, an allyl group, a methacryloyl group, an acryloyl group, or a maleimide group. The thermosetting compound (A) more preferably contains a thermosetting compound having an epoxy group, a vinyl group, a styryl group, a benzoxazine group, a cyanate group, an allyl group, a methacryloyl group, or a maleimide group. In this case, the effects of the present invention can be more effectively exhibited.

[0035] The molecular weight of the thermosetting compound (A) is preferably 100 or more, more preferably 200 or more, even more preferably 300 or more, and preferably 200,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less. When the molecular weight is above the lower limit and below the upper limit, a resin material with high fluidity during the formation of an insulating layer is easily obtained, and lamination properties can be improved. Furthermore, because lamination properties can be improved, the plating peel strength of the cured product can be further improved.

[0036] The molecular weight of the thermosetting compound (A) means a molecular weight that can be calculated from the structural formula when the thermosetting compound (A) is not a polymer and when the structural formula of the thermosetting compound (A) can be identified. When the thermosetting compound (A) is a polymer, the molecular weight means a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0037] The content of the thermosetting compound (A) in the resin material (100% by weight, excluding the solvent) is preferably 1% by weight or more, more preferably 3% by weight or more, even more preferably 10% by weight or more, particularly preferably 20% by weight or more, and preferably 60% by weight or less, more preferably 50% by weight or less. When the content of the thermosetting compound (A) is equal to or more than the above lower limit and equal to or less than the above upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0038] The content of the thermosetting compound (A) in the resin material, based on 100% by weight of the components excluding the hollow inorganic particles (B), the solid inorganic particles (C) and the solvent, is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 20% by weight or more, even more preferably 30% by weight or more, still more preferably 40% by weight or more, particularly preferably 50% by weight or more, preferably 100% by weight or less, more preferably 95% by weight or less. When the content of the thermosetting compound (A) is equal to or more than the above lower limit and equal to or less than the above upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0039] <Thermosetting compound having an epoxy group (epoxy compound)> The thermosetting compound (A) may contain a thermosetting compound having an epoxy group (epoxy compound), or may be a thermosetting compound having an epoxy group (epoxy compound). The above epoxy compounds may be used alone or in combination of two or more.

[0040] Examples of the epoxy compound include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, bisphenol E type epoxy compounds, phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, biphenyl type epoxy compounds, biphenyl novolac type epoxy compounds, biphenol type epoxy compounds, naphthalene type epoxy compounds, fluorene type epoxy compounds, phenol aralkyl type epoxy compounds, naphthol aralkyl type epoxy compounds, dicyclopentadiene type epoxy compounds, anthracene type epoxy compounds, epoxy compounds having an adamantane skeleton, epoxy compounds having a tricyclodecane skeleton, naphthylene ether type epoxy compounds, and epoxy compounds having a triazine nucleus in the skeleton.

[0041] The epoxy compound may be a glycidyl ether compound, which is a compound having at least one glycidyl ether group.

[0042] The epoxy compound preferably contains an epoxy compound having an aromatic ring, more preferably contains an epoxy compound having a naphthalene skeleton or a phenyl skeleton, and even more preferably contains an epoxy compound having an aromatic ring. In this case, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0043] From the viewpoint of further reducing the dielectric constant and dielectric dissipation factor of the cured product and improving the coefficient of linear expansion (CTE) of the cured product, the epoxy compound preferably contains an epoxy compound that is liquid at 25°C, and more preferably contains an epoxy compound that is liquid at 25°C and an epoxy compound that is solid at 25°C. In particular, when the epoxy compound contains an epoxy compound that is liquid at 25°C, a resin material with high fluidity is easily obtained when forming an insulating layer, and good lamination properties can be achieved. Furthermore, because good lamination properties can be achieved, the plating peel strength of the cured product can be further improved.

[0044] The viscosity at 25° C. of the epoxy compound that is liquid at 25° C. is preferably 10,000 mPa·s or less, and more preferably 5,000 mPa·s or less. The viscosity at 25° C. of the epoxy compound that is liquid at 25° C. may be 1 mPa·s or more, 10 mPa·s or more, or 100 mPa·s or more.

[0045] The viscosity of the epoxy compound can be measured using, for example, a dynamic viscoelasticity measuring device ("VAR-100" manufactured by Rheologica Instruments).

[0046] It is more preferable that the molecular weight of the epoxy compound is 1000 or less. In this case, a resin material with high fluidity is easily obtained when forming an insulating layer, and lamination properties can be improved. Furthermore, since lamination properties can be improved, the plating peel strength of the cured product can be further improved. The molecular weight of the epoxy compound may be 100 or more, or may be 200 or more.

[0047] The molecular weight of the epoxy compound means a molecular weight that can be calculated from the structural formula when the epoxy compound is not a polymer and when the structural formula of the epoxy compound can be identified, or when the epoxy compound is a polymer, means a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0048] The content of the epoxy compound in the resin material, based on 100% by weight of all components excluding the solvent, is preferably 1% by weight or more, more preferably 3% by weight or more, and preferably 60% by weight or less, more preferably 50% by weight or less. When the content of the epoxy compound is equal to or more than the lower limit and equal to or less than the upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0049] <Thermosetting compound (vinyl compound) having a vinyl group> The thermosetting compound (A) may contain a thermosetting compound (vinyl compound) having a vinyl group, or may be a thermosetting compound (vinyl compound) having a vinyl group. The vinyl compound may be used alone or in combination of two or more.

[0050] The vinyl compound includes a divinylbenzyl ether compound.

[0051] The content of the vinyl compound in the resin material, based on 100% by weight of all components excluding the solvent, is preferably 1% by weight or more, more preferably 3% by weight or more, and preferably 60% by weight or less, more preferably 50% by weight or less. When the content of the vinyl compound is equal to or more than the lower limit and equal to or less than the upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0052] <Thermosetting compound having a styryl group (styryl compound)> The thermosetting compound (A) may contain a thermosetting compound having a styryl group (styryl compound), or may be a thermosetting compound having a styryl group (styryl compound). The above styryl compounds may be used alone or in combination of two or more.

[0053] Commercially available styryl compounds include "OPE-2St" and "OPE-1200" manufactured by Mitsubishi Gas Chemical Company, Inc.

[0054] The content of the styryl compound in the resin material (100% by weight, excluding the solvent) is preferably 1% by weight or more, more preferably 3% by weight or more, and preferably 60% by weight or less, more preferably 50% by weight or less. When the content of the styryl compound is equal to or more than the lower limit and equal to or less than the upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0055] <Thermosetting compound having a benzoxazine group (benzoxazine compound)> The thermosetting compound (A) may contain a thermosetting compound having a benzoxazine group (benzoxazine compound), or may be a thermosetting compound having a benzoxazine group (benzoxazine compound). The above-mentioned benzoxazine compounds may be used alone or in combination of two or more.

[0056] Examples of the benzoxazine compound include Pd-type benzoxazine and Fa-type benzoxazine.

[0057] Commercially available products of the above benzoxazine compounds include "Pd type" manufactured by Shikoku Chemical Industry Co., Ltd.

[0058] The content of the benzoxazine compound is preferably 1 wt % or more, more preferably 3 wt % or more, and preferably 60 wt % or less, more preferably 50 wt % or less, based on 100 wt % of the components in the resin material excluding the solvent. When the content of the benzoxazine compound is equal to or more than the above lower limit and equal to or less than the above upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0059] <Thermosetting compound having a cyanate group (cyanate compound)> The thermosetting compound (A) may contain a thermosetting compound having a cyanate group (cyanate compound), or may be a thermosetting compound having a cyanate group (cyanate compound). The above cyanate compounds may be used alone or in combination of two or more.

[0060] The cyanate compound is preferably a cyanate ester compound.

[0061] Examples of the cyanate ester compounds include novolac cyanate ester resins, bisphenol cyanate ester resins, and prepolymers of these partially trimerized resins. Examples of the novolac cyanate ester resins include phenol novolac cyanate ester resins and alkylphenol cyanate ester resins. Examples of the bisphenol cyanate ester resins include bisphenol A cyanate ester resins, bisphenol E cyanate ester resins, and tetramethylbisphenol F cyanate ester resins.

[0062] Commercially available cyanate ester compounds include bisphenol A cyanate ester resins ("P-201" manufactured by Mitsubishi Gas Chemical Company, Inc.), phenol novolac cyanate ester resins ("PT-30" and "PT-60" manufactured by Lonza Japan), and prepolymers obtained by trimerizing bisphenol cyanate ester resins ("BA-230S," "BA-3000S," "BTP-1000S," and "BTP-6020S" manufactured by Lonza Japan).

[0063] The content of the cyanate compound in the resin material, based on 100% by weight of all components excluding the solvent, is preferably 1% by weight or more, more preferably 3% by weight or more, and preferably 60% by weight or less, more preferably 50% by weight or less. When the content of the cyanate compound is equal to or more than the lower limit and equal to or less than the upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0064] <Thermosetting compound (methacrylic compound) having a methacryloyl group> The thermosetting compound (A) may contain a thermosetting compound (methacrylic compound) having a methacryloyl group, or may be a thermosetting compound (methacrylic compound) having a methacryloyl group. The above methacrylic compounds may be used alone or in combination of two or more.

[0065] Commercially available products of the above methacrylic compound include "SA9000-111" manufactured by SABIC.

[0066] The content of the methacrylic compound in 100% by weight of the components excluding the solvent in the resin material is preferably 1% by weight or more, more preferably 3% by weight or more, and preferably 60% by weight or less, more preferably 50% by weight or less. When the content of the methacrylic compound is equal to or more than the above lower limit and equal to or less than the above upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0067] <Thermosetting Compound Having Maleimide Group (Maleimide Compound)> The thermosetting compound (A) may contain a thermosetting compound having a maleimide group (maleimide compound), or may be a thermosetting compound having a maleimide group (maleimide compound). The above maleimide compounds may be used alone or in combination of two or more.

[0068] The maleimide compound may have one maleimide group, two maleimide groups, two or more maleimide groups, three or more maleimide groups, four or more maleimide groups, or 800 or less maleimide groups, 500 or less maleimide groups, or 300 or less maleimide groups.

[0069] From the viewpoint of further reducing the dielectric constant and dielectric loss tangent of the cured product, the maleimide compound preferably contains a maleimide compound having two maleimide groups, and more preferably is a maleimide compound having two maleimide groups. Accordingly, the maleimide compound preferably contains a bismaleimide compound, and more preferably is a bismaleimide compound.

[0070] The maleimide compound preferably has an aliphatic skeleton or an alicyclic skeleton, and more preferably has both an aliphatic skeleton and an alicyclic skeleton. In this case, the effects of the present invention can be more effectively exhibited. In addition, the desmear property and plating peel strength can be improved.

[0071] Examples of the aliphatic skeleton include a chain aliphatic skeleton, and examples thereof include a saturated hydrocarbon group and an unsaturated hydrocarbon group. The aliphatic skeleton is preferably an aliphatic skeleton having 4 or more carbon atoms. The number of carbon atoms in the aliphatic skeleton having 4 or more carbon atoms is preferably 5 or more, more preferably 6 or more, even more preferably 7 or more, and preferably 60 or less, more preferably 50 or less, and even more preferably 40 or less. More specific examples of the aliphatic skeleton include alkyl groups having 4 to 60 carbon atoms (preferably alkyl groups having 6 to 40 carbon atoms). The maleimide compound may have only one type of aliphatic skeleton, or may have two or more types of aliphatic skeletons.

[0072] Examples of the alicyclic skeleton include a monocycloalkane ring, a bicycloalkane ring, a tricycloalkane ring, a tetracycloalkane ring, a dicyclopentadiene ring, etc. The maleimide compound may have only one type of alicyclic skeleton or two or more types of alicyclic skeletons.

[0073] From the viewpoint of further increasing the glass transition temperature of the cured product, the maleimide compound preferably has an aromatic skeleton.

[0074] Examples of the aromatic skeleton include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a tetracene ring, a chrysene ring, a triphenylene ring, a tetraphene ring, a pyrene ring, a pentacene ring, a picene ring, and a perylene ring. The maleimide compound may have only one type of aromatic skeleton or two or more types of aromatic skeletons.

[0075] The maleimide compound preferably has a skeleton derived from dimer diamine. Because the maleimide compound having a skeleton derived from dimer diamine has an aliphatic skeleton and an alicyclic skeleton, the use of the maleimide compound can further reduce the dielectric constant and dielectric dissipation factor of the cured product.

[0076] Examples of the dimer diamine (commercially available dimer diamine) include "VERSAMINE 551" (3,4-bis(1-aminoheptyl)-6-hexyl-5-(1-octenyl)cyclohexene) manufactured by BASF Japan, "VERSAMINE 552" (a hydrogenated product of VERSAMINE 551) manufactured by Cognix Japan, and "PRIAMINE 1075" and "PRIAMINE 1074" manufactured by Croda Japan. Only one type of the dimer diamine may be used, or two or more types may be used in combination.

[0077] The maleimide compound preferably has a skeleton derived from dimer diamine and a skeleton derived from a second diamine compound other than dimer diamine, in which case the effects of the present invention can be more effectively exhibited.

[0078] Examples of the second diamine compound include tricyclodecanediamine, norbornanediamine, isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.02,6]decane, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), 1,4-diaminobutanediamine, ... Examples of the second diamine compound include hexane, 1,10-diaminodecane, 1,12-diaminododecane, 1,7-diaminoheptane, 1,6-diaminohexane, 1,5-diaminopentane, 1,8-diaminooctane, 1,3-diaminopropane, 1,11-diaminoundecane, 2-methyl-1,5-diaminopentane, 1,1-bis(4-aminophenyl)cyclohexane, 2,7-diaminofluorene, 4,4'-ethylenedianiline, 4,4'-methylenebis(2,6-diethylaniline), and 4,4'-methylenebis(2-ethyl-6-methylaniline). Only one type of the second diamine compound may be used, or two or more types may be used in combination.

[0079] The second diamine compound may or may not have an aliphatic skeleton. The second diamine compound may or may not have an alicyclic skeleton. The second diamine compound may or may not have an aromatic skeleton.

[0080] The second diamine compound preferably includes a diamine compound having an alicyclic skeleton other than dimer diamine. The maleimide compound preferably has a skeleton derived from dimer diamine and a skeleton derived from a diamine compound having an alicyclic skeleton other than dimer diamine. In this case, the effects of the present invention can be more effectively exhibited.

[0081] The diamine compound having an alicyclic skeleton other than the dimer diamine is preferably tricyclodecane diamine, norbornane diamine, or isophorone diamine, in which case the effects of the present invention can be more effectively exhibited.

[0082] The maleimide compound preferably has a skeleton derived from an acid dianhydride, more preferably has a skeleton derived from a reaction product of a diamine compound and an acid dianhydride, and further preferably has a skeleton derived from a reaction product of a dimer diamine and an acid dianhydride.

[0083] Examples of the acid dianhydride include tetracarboxylic dianhydrides, such as pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenylethertetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3',4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, and 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfonyl ether. Examples of the acid dianhydride include 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylether dianhydride, and bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride. The above acid dianhydrides may be used alone or in combination of two or more.

[0084] The molecular weight of the maleimide compound is preferably 200 or more, more preferably 500 or more, even more preferably 1,000 or more, and preferably 200,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less. When the molecular weight is equal to or greater than the lower limit and equal to or less than the upper limit, a resin material with high fluidity during the formation of an insulating layer is easily obtained, and lamination properties can be improved. Furthermore, since lamination properties can be improved, the plating peel strength of the cured product can be further improved.

[0085] The molecular weight of the maleimide compound refers to a molecular weight that can be calculated from the structural formula when the maleimide compound is not a polymer or when the structural formula of the maleimide compound can be identified. When the maleimide compound is a polymer, the molecular weight refers to a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0086] Commercially available maleimide compounds include "NE-X-9470S" manufactured by DIC Corporation, "MIR-5000-60T" and "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., "BMI-3000J," "BMI-2500," "BMI-1500," and "BMI-689" manufactured by Designer Molecules Inc., and "BMI," "BMI-70," and "BMI-80" manufactured by K.I. Chemical Co., Ltd.

[0087] The maleimide compound can also be obtained by, for example, reacting an acid dianhydride such as a tetracarboxylic dianhydride with a diamine compound to obtain a reaction product, and then reacting the reaction product with maleic anhydride.

[0088] The content of the maleimide compound in the resin material (100% by weight, excluding the solvent) is preferably 1% by weight or more, more preferably 3% by weight or more, and preferably 60% by weight or less, more preferably 50% by weight or less. When the content of the maleimide compound is equal to or greater than the lower limit and equal to or less than the upper limit, the lamination properties can be further improved. Furthermore, the surface roughness after the roughening treatment can be further reduced, and the plating peel strength of the cured product can be further increased.

[0089] [Hollow Inorganic Particles (B)] The resin material contains hollow inorganic particles (B). The hollow inorganic particles (B) may be used alone or in combination of two or more types.

[0090] The hollow inorganic particles (B) are inorganic particles having a hollow. The hollow inorganic particles (B) have a hollow and an outer shell surrounding the hollow. The number of the hollow surrounded by the outer shell is usually one.

[0091] The hollow inorganic particles (B) are formed of an inorganic material. More specifically, the outer shell of the hollow inorganic particles (B) is formed of an inorganic material.

[0092] Examples of inorganic substances that form the hollow inorganic particles (B) include silica, aluminosilicate, silsesquioxane, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. The above inorganic substances may be used alone or in combination of two or more.

[0093] The inorganic substance forming the hollow inorganic particles (B) preferably contains silica, aluminosilicate, or silsesquioxane, more preferably contains silica or aluminosilicate, even more preferably contains silica, and particularly preferably is silica. The hollow inorganic particles (B) preferably contain hollow silica particles, hollow aluminosilicate particles, or hollow silsesquioxane particles, more preferably contains hollow silica particles or hollow aluminosilicate particles, even more preferably contains hollow silica particles, and particularly preferably is hollow silica particles. In this case, the dielectric constant and dielectric loss tangent of the cured product of the resin material can be further reduced.

[0094] From the viewpoint of suppressing cracking of the hollow inorganic particles during ultrasonic treatment, the root mean square height Rq of the outer surface of the hollow inorganic particles (B) is 2 nm or more. Furthermore, by making the root mean square height Rq of the outer surface of the hollow inorganic particles (B) 2 nm or more, cracking of the hollow inorganic particles during lamination can also be suppressed.

[0095] The root mean square height Rq of the outer surface of the hollow inorganic particles (B) is preferably 2.1 nm or more, more preferably 2.5 nm or more, and preferably 50 nm or less, more preferably 30 nm or less. When the root mean square height Rq is equal to or greater than the lower limit and equal to or less than the upper limit, cracking of the hollow inorganic particles during ultrasonic treatment and lamination can be more effectively suppressed.

[0096] The root mean square height Rq of the outer surface of the hollow inorganic particles (B) can be determined using an atomic force microscope (AFM). Specifically, it can be determined as follows.

[0097] A thin layer of epoxy resin is applied to the surface of a silicon wafer. Hollow inorganic particles are sprinkled on the surface of the applied epoxy resin to prepare a sample. This sample is set in an atomic force microscope (AFM) (e.g., Oxford Instruments' "Cypher ES"). Measurements are performed using an AC160 probe at a scan rate of 1 Hz in AM-FM mode. A square region is set whose side length is approximately the same as the radius of the hollow inorganic particles (B). The shape of this square region is measured using 256 x 256 pixels, and smoothing correction is performed using a cubic equation. In this way, the root-mean-square height Rq of the outer surface of the hollow inorganic particles (B) can be determined.

[0098] The hollow inorganic particles (B) preferably have an average particle size of 50 nm or more, more preferably 75 nm or more, even more preferably 100 nm or more, and preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 2 μm or less. When the average particle size is equal to or greater than the lower limit and equal to or less than the upper limit, the surface roughness after etching can be reduced, the plating peel strength can be increased, and the adhesion between the insulating layer and the metal layer can be further improved. In addition, short circuits between wirings can be further suppressed.

[0099] The median diameter (d50) at 50% is used as the average particle diameter of the hollow inorganic particles (B). The average particle diameter can be measured using a laser diffraction / scattering particle size distribution analyzer. When the hollow inorganic particles (B) are agglomerated particles, the average particle diameter of the hollow inorganic particles (B) refers to the primary particle diameter.

[0100] The shape of the hollow inorganic particles (B) is not particularly limited, but is preferably spherical. In this case, the surface roughness of the cured product is effectively reduced, and the adhesive strength between the cured product and the metal layer is effectively increased. When the hollow inorganic particles (B) are spherical, the aspect ratio of the hollow inorganic particles (B) is preferably 1 or more, preferably 2 or less, more preferably 1.5 or less.

[0101] The number of holes (number of hollows) contained inside the hollow inorganic particles (B) is not particularly limited, but it is preferable that the number is one.

[0102] The porosity of the hollow inorganic particles (B) is preferably 20% by volume or more, more preferably 30% by volume or more, even more preferably 40% by volume or more, and preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less. When the porosity is equal to or more than the lower limit and equal to or less than the upper limit, the dielectric constant and dielectric loss tangent of the cured product of the resin material can be further reduced.

[0103] When the number of holes (number of hollows) contained inside the hollow inorganic particles (B) is one, the porosity can be calculated as follows. The hollow inorganic particles (B) are photographed using a transmission electron microscope (TEM). From the obtained micrograph, the particle diameters of 50 arbitrary hollow inorganic particles (B) are measured, and the average value is taken as the average particle diameter (X). Furthermore, the hollow inorganic particles (B) are cut in half, and the cut hollow inorganic particles (B) are photographed using a transmission electron microscope (TEM). From the obtained micrograph, the diameters of the cavities of the cut surfaces of 50 arbitrary cut hollow inorganic particles (B) are measured, and the average value is taken as the average diameter (Y) of the cavities. The porosity is calculated using the following formula:

[0104] Porosity (volume%) = (Y ３ / X ３ ) × 100 X: average particle diameter (X) Y: average diameter of cavity (Y)

[0105] When the number of pores (number of hollows) contained inside the hollow inorganic particles (B) is 2 or more, the porosity can also be determined using a transmission electron microscope (TEM) from the volume of the hollow inorganic particles (B) determined from the particle diameter of the hollow inorganic particles (B) and the volume of the hollow portions determined from the diameter of the hollow portions.

[0106] The hollow inorganic particles (B) are preferably surface-treated hollow inorganic particles, more preferably surface-treated with a coupling agent. By surface-treating the hollow inorganic particles (B), the surface roughness of the cured product is further reduced, and the adhesive strength between the cured product and the metal layer is further increased. Furthermore, by surface-treating the hollow inorganic particles (B), it is possible to form finer wiring on the surface of the cured product, and to impart better inter-wiring insulation reliability and inter-layer insulation reliability to the cured product.

[0107] Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent, etc. Examples of the silane coupling agent include methacrylsilane, acrylsilane, phenylaminosilane, phenylsilane, imidazolesilane, vinylsilane, alkylaminosilane, and epoxysilane.

[0108] The hollow inorganic particles (B) are preferably hollow inorganic particles surface-treated with a silane coupling agent, more preferably hollow inorganic particles surface-treated with vinylsilane, phenylaminosilane, or phenylsilane. In this case, the lamination property can be further improved. Furthermore, since the lamination property can be improved, the plating peel strength of the cured product can be further improved.

[0109] The content of hollow inorganic particles (B) in the resin material, based on 100% by weight of the components excluding the solvent, is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 15% by weight or more, and preferably 60% by weight or less, more preferably 55% by weight or less, and even more preferably 50% by weight or less. When the content of hollow inorganic particles (B) is above the lower limit, the dielectric constant and dielectric dissipation factor of the cured resin material can be further reduced. Furthermore, thermal dimensional stability can be improved, and warping of the cured product can be effectively suppressed. When the content of hollow inorganic particles (B) is above the lower limit and below the upper limit, the surface roughness of the cured product can be further reduced, and short circuits between wirings can be further suppressed, resulting in the formation of finer wiring on the surface of the cured product. Furthermore, this content of hollow inorganic particles (B) can reduce the thermal expansion coefficient of the cured product while also improving smear removal properties.

[0110] In the resin material, the weight ratio of the content of hollow inorganic particles (B) to the content of thermosetting compound (A) (content of hollow inorganic particles (B) / content of thermosetting compound (A)) is preferably 0.1 or more, more preferably 0.2 or more, and preferably 3 or less, more preferably 2.5 or less. When the weight ratio (content of hollow inorganic particles (B) / content of thermosetting compound (A)) is equal to or more than the above lower limit and equal to or less than the above upper limit, the effects of the present invention can be more effectively exhibited.

[0111] [Solid Inorganic Particles (C)] The resin material may contain solid inorganic particles (C). The solid inorganic particles (C) may be used alone or in combination of two or more types.

[0112] The solid inorganic particles (C) are inorganic particles that do not have a hollow space.

[0113] Examples of the solid inorganic particles (C) include solid silica particles, solid talc particles, solid clay particles, solid mica particles, solid hydrotalcite particles, solid alumina particles, solid magnesium oxide particles, solid aluminum hydroxide particles, solid aluminum nitride particles, and solid boron nitride particles.

[0114] From the viewpoints of reducing the surface roughness of the surface of the cured product, further increasing the adhesive strength between the cured product and the metal layer, forming finer wiring on the surface of the cured product, and imparting better insulation reliability to the cured product, the solid inorganic particles (C) are preferably solid silica particles or solid alumina particles, and more preferably solid silica particles.

[0115] The solid inorganic particles (C) have an average particle size of preferably 50 nm or more, more preferably 100 nm or more, even more preferably 500 nm or more, and preferably 5 μm or less, more preferably 3 μm or less, and even more preferably 1 μm or less. When the average particle size of the solid inorganic particles (C) is equal to or greater than the above lower limit and equal to or less than the above upper limit, the surface roughness after etching can be reduced, the plating peel strength can be increased, and the adhesion between the insulating layer and the metal layer can be further improved.

[0116] The median diameter (d50) at 50% is used as the average particle diameter of the solid inorganic particles (C). The average particle diameter can be measured using a laser diffraction / scattering particle size distribution analyzer.

[0117] The shape of the solid inorganic particles (C) is not particularly limited, but is preferably spherical. In this case, the surface roughness of the cured product is effectively reduced, and the adhesive strength between the cured product and the metal layer is effectively increased. When the solid inorganic particles (C) are spherical, the aspect ratio of the solid inorganic particles (C) is preferably 1 or more, preferably 2 or less, more preferably 1.5 or less.

[0118] The solid inorganic particles (C) are preferably surface-treated, more preferably surface-treated with a coupling agent, and even more preferably surface-treated with a silane coupling agent. By surface-treating the solid inorganic particles (C), the surface roughness of the cured product is further reduced, and the adhesive strength between the cured product and the metal layer is further increased. Furthermore, by surface-treating the solid inorganic particles (C), it is possible to form finer wiring on the surface of the cured product, and to impart better inter-wiring insulation reliability and inter-layer insulation reliability to the cured product.

[0119] Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent, etc. Examples of the silane coupling agent include methacrylsilane, acrylsilane, aminosilane, imidazolesilane, vinylsilane, and epoxysilane.

[0120] The content of the solid inorganic particles (C) in the resin material, based on 100% by weight of the components excluding the solvent, is preferably 1% by weight or more, more preferably 5% by weight or more, preferably 75% by weight or less, more preferably 70% by weight or less, and even more preferably 65% ​​by weight or less. When the content of the solid inorganic particles (C) is above the above-mentioned lower limit, the dielectric constant and dielectric dissipation factor of the cured product of the resin material can be further reduced. In addition, the thermal dimensional stability can be improved, and warping of the cured product can be effectively suppressed. When the content of the solid inorganic particles (C) is above the above-mentioned lower limit and below the above-mentioned upper limit, the surface roughness of the cured product can be further reduced, and finer wiring can be formed on the surface of the cured product. Furthermore, this content of the solid inorganic particles (C) can reduce the thermal expansion coefficient of the cured product while also improving smear removal properties.

[0121] [Curing Accelerator (D)] The resin material preferably contains a curing accelerator (D). The use of the curing accelerator (D) further accelerates the curing rate. Rapid curing of the resin material results in a uniform crosslinked structure in the cured product, a reduced number of unreacted functional groups, and a higher crosslink density. Furthermore, the use of the curing accelerator (D) allows the resin material to be cured well even at a relatively low temperature. Only one type of curing accelerator (D) may be used, or two or more types may be used in combination.

[0122] Examples of the curing accelerator (D) include anionic curing accelerators such as imidazole compounds; cationic curing accelerators such as amine compounds; curing accelerators other than anionic and cationic curing accelerators such as organophosphorus compounds and organometallic compounds; and radical curing accelerators such as peroxides and azo compounds.

[0123] 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-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, and 1-cyanoethyl-2-phenylimidazolium trimethylolate. limeritate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine 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.

[0124] Examples of the amine compound include diethylamine, triethylamine, diethylenetetramine, triethylenetetramine, diethylenetriamine, ethylenediamine, tris(dimethylaminomethyl)phenol, benzyldimethylamine, m-xylylenedi(dimethylamine), N,N'-dimethylpiperazine, N-methylpyrrolidine, N-methylhydroxypiperidine, m-xylylenediamine, isophoronediamine, N-aminoethylpiperazine, polyoxypropylenepolyamine, and 4,4-dimethylaminopyridine. The amine compound may also be a modified product of any of these amine compounds.

[0125] Examples of the organic phosphorus compound include organic phosphine compounds such as triphenylphosphine, tricyclohexylphosphine, tribenzylphosphine, diphenyl(alkylphenyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkylalkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, and alkyldiarylphosphine; and phosphonium salt compounds such as tetraphenylphosphonium tetraphenylborate.

[0126] Examples of the organometallic compound include zinc naphthenate, cobalt naphthenate, tin octoate, cobalt octoate, bisacetylacetonate cobalt (II), and trisacetylacetonate cobalt (III).

[0127] Examples of the peroxide include diacyl peroxides, peroxyesters, peroxydicarbonates, monoperoxycarbonates, peroxyketals, dialkyl peroxides, dibenzyl peroxide, dicumyl peroxide, hydroperoxides, and ketone peroxides.

[0128] The curing accelerator (D) preferably contains an amine compound, an imidazole compound, a peroxide, an azo compound, or an organic phosphorus compound, and more preferably contains an imidazole compound or a peroxide, in which case the effects of the present invention can be more effectively exhibited.

[0129] In the resin material, the content of the curing accelerator (D) relative to 100 parts by weight of the thermosetting compound (A) is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, and preferably 10 parts by weight or less, more preferably 5 parts by weight or less. When the content of the curing accelerator (D) is equal to or more than the above lower limit and equal to or less than the above upper limit, the effects of the present invention can be more effectively exhibited.

[0130] [Curing agent (E)] The resin material preferably contains a curing agent (E). The curing agent (E) is not particularly limited. As the curing agent (E), a conventionally known curing agent can be used. Only one type of curing agent (E) may be used, or two or more types may be used in combination.

[0131] Examples of the curing agent (E) include a compound having an active ester group (active ester compound), a compound having a hydroxyl group, a compound having a thiol group, and a compound having an amino group. The curing agent (E) preferably contains an active ester compound.

[0132] The content of the curing agent (E) in the resin material is appropriately selected depending on, for example, the content of the thermosetting compound (A) in the resin material.

[0133] [Solvent] The resin material contains or does not contain a solvent. The resin material may contain or may not contain a solvent. By using the solvent, the viscosity of the resin material can be controlled within a suitable range, and the coatability of the resin material can be improved. The solvent may also be used to obtain a slurry containing hollow inorganic particles (B). Only one type of the solvent may be used, or two or more types may be used in combination.

[0134] Examples of the solvent include acetone, methanol, ethanol, butanol, 2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 2-acetoxy-1-methoxypropane, toluene, xylene, methyl ethyl ketone, N,N-dimethylformamide, methyl isobutyl ketone, N-methyl-pyrrolidone, n-hexane, cyclohexane, cyclohexanone, and naphtha, which is a mixture.

[0135] It is preferable that most of the solvent is removed when the resin composition is formed into a film. Therefore, the boiling point of the solvent is preferably 200°C or lower, more preferably 180°C or lower. The boiling point of the solvent may be 30°C or higher, 50°C or higher, or 100°C or higher. The content of the solvent in the resin composition is not particularly limited. The content of the solvent can be appropriately changed taking into account the coatability of the resin composition, etc.

[0136] When the resin material is a B-stage film, the content of the solvent in 100% by weight of the B-stage film is preferably 1% by weight or more, more preferably 2% by weight or more, preferably 15% by weight or less, more preferably 10% by weight or less.

[0137] [Other Components] For the purpose of improving impact resistance, heat resistance, resin compatibility, workability, etc., the resin material may contain other components in addition to the above-mentioned components (thermosetting compound (A), hollow inorganic particles (B), solid inorganic particles (C), curing accelerator (D), curing agent (E), and solvent). Examples of the other components include thermoplastic resins; organic fillers; leveling agents; flame retardants; coupling agents; colorants; antioxidants; ultraviolet degradation inhibitors; antifoaming agents; thickeners; thixotropy-imparting agents, etc. One type of the other components may be used alone, or two or more types may be used in combination.

[0138] Examples of the thermoplastic resin include polyimide resin, phenoxy resin, and polyvinyl acetal resin.

[0139] Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent, etc. Examples of the silane coupling agent include vinyl silane, amino silane, imidazole silane, and epoxy silane.

[0140] The resin material may or may not contain glass cloth. The resin material preferably does not contain glass cloth. The resin material preferably is not a prepreg.

[0141] (Resin film) A resin film (B-staged product / B-stage film) can be obtained by molding the above-mentioned resin composition into a film. The above-mentioned resin material is preferably a resin film. The resin film is preferably a B-stage film.

[0142] Examples of methods for forming a resin composition into a film to obtain a resin film include the following: an extrusion molding method in which a resin composition is melt-kneaded using an extruder, extruded, and then formed into a film using a T-die, circular die, or the like; a casting molding method in which a resin composition containing a solvent is cast into a film; and other conventionally known film forming methods. Extrusion molding and casting molding are preferred because they can be used to make thinner films. Films include sheets.

[0143] The resin composition is formed into a film and dried by heating, for example, at 50°C to 150°C for 1 minute to 10 minutes to the extent that curing by heat does not proceed too much, to obtain a resin film that is a B-stage film.

[0144] The film-like resin composition obtained by the drying process described above is called a B-stage film. The B-stage film is in a semi-cured state. The semi-cured product is not completely cured, and curing can continue.

[0145] The resin film does not have to be a prepreg. When the resin film is not a prepreg, migration does not occur along the glass cloth or the like. Furthermore, when the resin film is laminated or precured, irregularities due to the glass cloth do not occur on the surface.

[0146] The resin film can be used in the form of a laminated film comprising a metal foil or a base film and a resin film laminated on the surface of the metal foil or the base film. The metal foil is preferably a copper foil.

[0147] Examples of the substrate film of the laminated film include polyester resin films such as polyethylene terephthalate film and polybutylene terephthalate film, olefin resin films such as polyethylene film and polypropylene film, and polyimide resin films. The surface of the substrate film may be subjected to a release treatment, if necessary.

[0148] From the viewpoint of controlling the degree of cure of the resin film more uniformly, the thickness of the resin film is preferably 5 μm or more and preferably 200 μm or less. When the resin film is used as an insulating layer of a circuit, the thickness of the insulating layer formed by the resin film is preferably equal to or greater than the thickness of the conductor layer (metal layer) that forms the circuit. The thickness of the insulating layer is preferably 5 μm or more and preferably 200 μm or less.

[0149] (Other Details of Resin Material) When the resin material is heated at 180°C for 30 minutes and then at 200°C for 60 minutes to obtain a cured product of the resin material, the dielectric constant (Dk) of the obtained cured product at 10 GHz is preferably 2.5 or less, more preferably less than 2.5, even more preferably 2.2 or less, even more preferably 2.0 or less, and particularly preferably less than 2.0. The dielectric constant (Dk) of the obtained cured product at 10 GHz may be 0 or more, or may exceed 0.

[0150] The dielectric constant (Dk) of the cured product at 10 GHz can be measured as follows. The resin material is heated at 180°C for 30 minutes, and then heated at 200°C for 60 minutes to obtain a cured product of the resin material. The dielectric constant (Dk) of the obtained cured product is measured by the cavity resonance method using a dielectric constant measuring device (for example, the "Cavity Resonance Perturbation Dielectric Constant Measuring Device CP521" manufactured by Kanto Electronics Application Development Co., Ltd.) at room temperature (23°C) and a frequency of 10 GHz.

[0151] When using the resin material to manufacture electronic components such as multilayer substrates, the resin material may be heated at 180°C for 30 minutes and then at 200°C for 60 minutes to obtain a cured product, or the resin material may be heated under heating conditions other than these to obtain a cured product.

[0152] The resin material can be used for various purposes. For example, the resin material is preferably used to form a mold resin in which a semiconductor chip is embedded in a semiconductor device. The resin material is also preferably used as a replacement for liquid crystal polymer (LCP), a millimeter-wave antenna, or a rewiring layer. The resin material is not limited to the above purposes, but is preferably used for wiring formation purposes in general.

[0153] The resin material is preferably used as an adhesive material. The resin material is preferably used as, for example, an adhesive material for power overlay packages, an adhesive material for printed wiring boards, an adhesive material for coverlays of flexible printed circuit boards, or an adhesive material for semiconductor bonding. The resin material is preferably an adhesive material.

[0154] The resin material is preferably used as an insulating material. The resin material is preferably used to form an insulating layer in a printed wiring board, and more preferably to form an insulating layer in a multilayer printed wiring board. The resin material is preferably an insulating material, and more preferably an interlayer insulating material. The insulating material may also serve as an adhesive material.

[0155] The cured product according to the present invention is a cured product of a resin material obtained by curing the resin material described above. The cured product according to the present invention is a cured product of a resin material, and the resin material is the resin material described above. The cured product according to the present invention can be obtained by curing the resin material described above. The heating conditions for the resin material when obtaining the cured product according to the present invention are not particularly limited, as long as the resin material is cured.

[0156] (Laminated structure and copper-clad laminate) A laminated structure can be obtained by laminating a lamination target member having a metal layer on one or both sides of the resin film. The laminated structure comprises a lamination target member having a metal layer on its surface and a resin film laminated on the surface of the metal layer, the resin film being the resin material described above. The method for laminating the resin film and the lamination target member is not particularly limited, and known methods can be used. For example, the resin film can be laminated onto the lamination target member using a device such as a parallel plate press or a roll laminator while applying pressure with or without heating.

[0157] The material of the metal layer is preferably copper.

[0158] The lamination target member having the metal layer on its surface may be a metal foil such as a copper foil.

[0159] The resin material is preferably used to obtain a copper-clad laminate. An example of the copper-clad laminate is a copper-clad laminate including a copper foil and a resin film laminated on one surface of the copper foil, the resin film being made of the resin material described above.

[0160] The thickness of the copper foil of the copper-clad laminate is not particularly limited. The thickness of the copper foil is preferably 1 μm or more and 100 μm or less. In addition, in order to increase the adhesive strength between the cured resin material and the copper foil, the copper foil preferably has fine irregularities on its surface. The method for forming the irregularities is not particularly limited. Examples of the method for forming the irregularities include a method using a known chemical solution, a known plasma treatment, and a known UV treatment.

[0161] (Circuit board with insulating layer) The resin material is suitably used to obtain a circuit board with an insulating layer. An example of the circuit board with an insulating layer includes a circuit board and an insulating layer disposed on the surface of the circuit board, the insulating layer being a cured product of the resin material described above.

[0162] In the circuit board with an insulating layer, the insulating layer is preferably laminated on the surface of the circuit board on which the circuits are provided, and a portion of the insulating layer is preferably embedded between the circuits.

[0163] The above-mentioned circuit board with an insulating layer can be obtained by a conventionally known method.

[0164] (Multilayer substrate and multilayer printed wiring board) The resin material is suitably used to obtain a multilayer substrate. An example of the multilayer substrate is a multilayer substrate including a circuit board and an insulating layer laminated on the circuit board. The insulating layer of the multilayer substrate is a cured product of the resin material described above. The insulating layer is preferably laminated on the surface of the circuit board on which the circuits (metal layer) are provided. A portion of the insulating layer is preferably embedded between the circuits.

[0165] In the multilayer substrate, the surface of the insulating layer opposite to the surface on which the circuit board is laminated is preferably roughened.

[0166] The roughening treatment method may be a conventionally known roughening treatment method, and is not particularly limited. The surface of the insulating layer may be subjected to a swelling treatment before the roughening treatment. After the roughening treatment, it is preferable to perform an ultrasonic treatment for the purpose of removing the hollow inorganic particles (B) (and the solid inorganic particles (C)) from the surface of the insulating layer.

[0167] Preferably, the multilayer substrate further comprises a copper plating layer laminated on the roughened surface of the insulating layer.

[0168] Another example of the multilayer substrate is a multilayer substrate comprising a circuit board, an insulating layer laminated on the surface of the circuit board, and copper foil laminated on the surface of the insulating layer opposite to the surface on which the circuit board is laminated. Preferably, the insulating layer is formed by using a copper-clad laminate comprising copper foil and a resin film laminated on one surface of the copper foil and curing the resin film. Furthermore, the copper foil is preferably etched to form a copper circuit.

[0169] Another example of the multilayer substrate is a multilayer substrate including a circuit board and a plurality of insulating layers laminated on a surface of the circuit board, at least one of the insulating layers disposed on the circuit board being formed using the resin material, and preferably the multilayer substrate further includes a circuit laminated on at least one surface of the insulating layer formed using the resin film.

[0170] The above resin material is suitably used to form an insulating layer in a multilayer printed wiring board.

[0171] The multilayer printed wiring board includes, for example, a circuit board, a plurality of insulating layers disposed on a surface of the circuit board, and a metal layer disposed between the plurality of insulating layers, and at least one of the insulating layers is a cured product of the resin material described above.

[0172] FIG. 1 is a cross-sectional view schematically showing a multilayer printed wiring board using a resin material according to one embodiment of the present invention.

[0173] In the multilayer printed wiring board 11 shown in FIG. 1, a plurality of insulating layers 13-16 are laminated on the upper surface 12a of a circuit board 12. The insulating layers 13-16 are cured layers. A metal layer 17 is formed on a partial region of the upper surface 12a of the circuit board 12. Of the plurality of insulating layers 13-16, the insulating layers 13-15 other than the insulating layer 16 located on the outer surface opposite the circuit board 12 have the metal layer 17 formed on a partial region of the upper surface. The metal layer 17 is a circuit. A metal layer 17 is disposed between the circuit board 12 and the insulating layer 13, and between each of the laminated insulating layers 13-16. The lower metal layer 17 and the upper metal layer 17 are connected to each other by at least one of via hole connections and through-hole connections (not shown).

[0174] In the multilayer printed wiring board 11, the insulating layers 13 to 16 are formed from a cured product of the resin material. In this embodiment, the surfaces of the insulating layers 13 to 16 are roughened, and thus fine holes (not shown) are formed in the surfaces of the insulating layers 13 to 16. The metal layer 17 extends into the fine holes. In addition, in the multilayer printed wiring board 11, the width dimension (L) of the metal layer 17 and the width dimension (S) of the portion where the metal layer 17 is not formed can be reduced. In addition, in the multilayer printed wiring board 11, good insulation reliability is provided between the upper metal layer and the lower metal layer that are not connected by via hole connections or through hole connections (not shown).

[0175] The present invention will be specifically described below by way of examples and comparative examples, but the present invention is not limited to the following examples.

[0176] The following materials were prepared:

[0177] (Thermosetting Compound (A)) Maleimide compound ("BMI3000J" manufactured by Designer Molecules Inc., a maleimide compound having an aliphatic skeleton, number of maleimide groups: 2, weight average molecular weight: 3000) Polyphenylene ether methacrylic acid compound ("SA9000-111" manufactured by SABIC, solid at 25°C) Divinylbenzene (viscosity at 25°C: 1 mPa·s) Oligophenylene ether styrene compound ("OPE-2St" manufactured by Mitsubishi Gas Chemical Company, Inc.) P-d type benzoxazine ("P-d" manufactured by Shikoku Chemical Industry Co., Ltd., solid at 25°C) Biphenyl type epoxy compound ("NC-3000" manufactured by Nippon Kayaku Co., Ltd., solid at 25°C) Bisphenol A cyanate ester resin ("P-201" manufactured by Mitsubishi Gas Chemical Company, Inc., viscosity at 25°C: 100 mPa·s)

[0178] (Hollow inorganic particles (B)) Hollow silica particles B1 ("HS-070" manufactured by AGC, root mean square height of outer surface Rq: 3 nm, average particle size: 0.6 μm, porosity: 70% by volume) Hollow silica particles B2 ("HS-200" manufactured by AGC, root mean square height of outer surface Rq: 15 nm, average particle size: 2.0 μm, porosity: 75% by volume)

[0179] (Hollow inorganic particles not corresponding to hollow inorganic particles (B)) Hollow silica particles X ("L6SZ-AC1" manufactured by Admatechs Co., Ltd., root mean square height of outer surface Rq: 1 nm, average particle size: 0.6 μm, porosity: 40% by volume) Hollow aluminosilicate particles ("CellSpheres-NF (small particle size)" manufactured by Taiheiyo Cement Corporation, root mean square height of outer surface Rq: 1 nm, average particle size: 1 μm, porosity: 75% by volume)

[0180] The root mean square height Rq, average particle size, and porosity of the outer surface of the hollow inorganic particles were measured according to the methods described above. The root mean square height Rq was measured using an atomic force microscope (AFM) manufactured by Oxford Instruments, Ltd., called a Cypher ES.

[0181] FIG. 2 shows an atomic force microscope photograph of the hollow silica particles B1.

[0182] (Solid inorganic particles (C)) Solid silica particles ("SC2050-HNG" manufactured by Admatechs Co., Ltd., average particle size: 0.5 μm)

[0183] (Curing accelerator (D)) Peroxide ("Perbutyl P" manufactured by NOF Corporation) Imidazole compound (2-phenyl-4-methylimidazole, "2P4MZ" manufactured by Shikoku Chemicals Corporation, anionic curing accelerator)

[0184] (Curing agent (E)) Active ester compound-containing liquid (DIC Corporation "HPC-8000L-65T", solid content 65% by weight)

[0185] (Examples 1 to 20 and Comparative Examples 1 to 5) The components shown in Tables 1 to 5 below were mixed in the amounts (unit: parts by weight of solid content) shown in Tables 1 to 5 below, and stirred at room temperature until a uniform solution was obtained, thereby obtaining a resin material.

[0186] Preparation of resin film: Using an applicator, the obtained resin material was applied to the release-treated surface of a release-treated polyethylene terephthalate film (PET film, "XG284" manufactured by Toray Industries, Inc., thickness 25 μm), and then dried for 2 minutes and 30 seconds in a gear oven at 100° C. to volatilize the solvent. In this way, a laminated film (a laminated film of PET film and resin film) was obtained in which a 40 μm-thick resin film (B-stage film) was laminated on the PET film.

[0187] (Evaluation) (1) Dielectric Constant (Dk) of Cured Product The obtained 40 μm thick resin film (B-stage film) was heated at 180° C. for 30 minutes, and then heated at 200° C. for 60 minutes to obtain a cured product. The obtained cured product was cut into a size of 2 mm wide and 80 mm long, and 10 sheets were stacked to obtain a measurement sample. The dielectric constant (Dk) of the cured product was measured at room temperature (23° C.) and a frequency of 10 GHz by the cavity resonance method using a "Cavity Resonance Perturbation Dielectric Constant Measuring Apparatus CP521" manufactured by Kanto Electronics Application Development Co., Ltd. and a "Network Analyzer N5224A PNA" manufactured by Keysight Technologies, Inc.

[0188] [Evaluation criteria for dielectric constant (Dk) of cured product] ○: Dielectric constant is less than 2.0 △: Dielectric constant is 2.0 or more and 2.5 or less ×: Dielectric constant is more than 2.5

[0189] (2) Lamination A 100 mm square substrate having a 1 mm x 2 mm rectangular depression was prepared by etching a copper layer having a thickness of 18 μm using a mask to etch a rectangular area measuring 1 mm x 2 mm. Both sides of the copper foil surface of this substrate were immersed in "Cz8101" manufactured by MEC Co., Ltd., to roughen the copper foil surface. Using a "batch vacuum laminator MVLP-500-IIA" manufactured by Meiki Seisakusho Co., Ltd., the resin film (B-stage film) side of the laminate film was laminated onto both sides of the roughened substrate to obtain a laminate structure. The lamination conditions were as follows: the pressure was reduced for 30 seconds to a pressure of 13 hPa or less, followed by lamination at 100 ° C and a pressure of 0.7 MPa for 30 seconds, and then pressing for 60 seconds at a pressure of 0.8 MPa and a press temperature of 100 ° C. The PET film was peeled off, and the resin film was semi-cured by heating at 100° C. for 30 minutes and then further heating at 180° C. for 30 minutes. The surface of the semi-cured resin film where the copper pattern was present (the surface opposite the substrate) and the surface of the semi-cured resin film where the copper pattern was not present (the surface opposite the substrate) were observed, and the maximum height difference between adjacent concave and convex portions was determined using an optical step gauge.

[0190] [Lamination criteria] ◯: Maximum height difference is less than 1.3 μm ○: Maximum height difference is 1.3 μm or more and less than 1.5 μm Δ: Maximum height difference is 1.5 μm or more and less than 2 μm ×: Maximum height difference is 2 μm or more

[0191] (3) Cracks in particles (hollow inorganic particles or solid inorganic particles) after lamination After the evaluation of "(2) Lamination property" above, the semi-cured resin film was cut into pieces measuring 2 cm x 1 cm. The resulting cut pieces were embedded in resin, and then the resin and the cut pieces were polished to expose the cross section of the cut piece (a cross section along the thickness direction of the semi-cured resin film). The exposed cross section was observed at a magnification of 5000x using a scanning electron microscope (SEM, "JSM-561 0LV" manufactured by JEOL Datum Co., Ltd.). 30 randomly selected particles were checked for the presence or absence of cracks.

[0192] [Criteria for determining cracks in particles after lamination] ◯: out of 30 particles, the number of cracked particles is 3 or less. ×: out of 30 particles, the number of cracked particles is 4 or more.

[0193] (4) Cracks in particles (hollow inorganic particles or solid inorganic particles) after ultrasonic treatment After the evaluation of "(2) Lamination property" above, the following "(4-1) Roughening treatment" and "(4-2) Observation with a scanning electron microscope" were performed.

[0194] (4-1) Roughening Treatment: (a) Swelling Treatment: The laminate of the substrate and the semi-cured resin film obtained in the above "(2) Lamination" was placed in a swelling liquid ("Swelling Dip Securigant P" manufactured by Atotech Japan) at 60°C and swung for 10 minutes. Thereafter, it was washed with pure water.

[0195] (b) Permanganate treatment (roughening treatment and desmear treatment): The laminate after the swelling treatment was placed in a roughening aqueous solution of potassium permanganate ("Concentrate Compact CP" manufactured by Atotech Japan) at 80° C. and shaken for 30 minutes. Next, the laminate was treated for 2 minutes using a cleaning solution ("Reduction Securigant P" manufactured by Atotech Japan) at 25° C., and then washed in pure water by applying ultrasonic vibrations at a frequency of 40 kHz for 200 seconds.

[0196] (4-2) Observation by Scanning Electron Microscope: The cured product after ultrasonic treatment (roughened cured product) was cut into pieces measuring 2 cm x 1 cm. The resulting cut pieces were embedded in resin, and then the resin and the cut pieces were polished to expose the cross section of the cut pieces (cross section along the thickness direction of the cured product). The exposed cross section was observed at a magnification of 5000x using a scanning electron microscope (SEM, "JSM-561 0LV" manufactured by JEOL Datum Co., Ltd.). 30 randomly selected particles were checked for the presence or absence of cracks.

[0197] [Criteria for determining whether particles are cracked after ultrasonic treatment] ◯: out of 30 particles, the number of cracked particles is 3 or less. ×: out of 30 particles, the number of cracked particles is 4 or more.

[0198] (5) Amount of Plating Penetration After the above "(4-1) Roughening Treatment", the below-described "(5-1) Electroless Plating Treatment" was carried out to obtain a cured product having a copper plating layer laminated on its upper surface. The obtained cured product having a copper plating layer laminated on its upper surface was used to carry out the below-described "(5-2) Measurement of the Amount of Plating Penetration".

[0199] (5-1) Electroless Plating Treatment: The roughened surface of the cured product was treated with an alkaline cleaner (Cleaner Securigant 902, manufactured by Atotech Japan) at 60°C for 5 minutes to degrease and clean. After cleaning, the cured product was treated with a pre-dip solution (Pre-dip Neogant B, manufactured by Atotech Japan) at 25°C for 2 minutes. The cured product was then treated with an activator solution (Activator Neogant 834, manufactured by Atotech Japan) at 40°C for 5 minutes to attach a palladium catalyst. Next, the cured product was treated with a reducing solution (Reducer Neogant WA, manufactured by Atotech Japan) at 30°C for 5 minutes. Next, the cured product was placed in a chemical copper solution (Basic Printgant MSK-DK, Copper Printgant MSK, Stabilizer Printgant MSK, and Reducer Cu, manufactured by Atotech Japan), and electroless plating was performed until the plating thickness reached approximately 0.5 μm. After electroless plating, the substrate was annealed at 120°C for 30 minutes to remove any remaining hydrogen gas. All steps up to the electroless plating step were carried out using a 2 L beaker of treatment solution while the cured product was being shaken. In this way, a cured product with a copper plating layer laminated on the upper surface was obtained.

[0200] (5-2) Measurement of plating penetration: Using an FE-SEM, the interface between the copper plating layer and the cured product in a cured product having a copper plating layer laminated thereon was observed at a magnification of 5000x. During observation, the cured product with the copper plating layer laminated thereon was positioned with the copper plating layer on top and the cured product on the bottom, with the interface between the copper plating layer and the cured product horizontal. As shown in FIG. 3 , in a 20 μm wide region of the obtained microscopic image, a line L1 was designated as the line that contacted the cured product at the top of the microscopic image and was parallel to the interface between the copper plating layer and the cured product. Also, as shown in FIG. 3 , a line L2 was designated as the line that contacted the copper plating at the bottom of the 20 μm wide region of the obtained microscopic image and was parallel to the interface between the copper plating layer and the cured product. As shown in FIG. 3 , the distance between lines L1 and L2 was designated the plating penetration D. The smaller the plating penetration D, the more likely it is that short circuits between wirings will be reduced.

[0201] [Criteria for determining the amount of penetration] ○: The amount of penetration D of the plating is less than 3 μm ×: The amount of penetration D of the plating is 3 μm or more

[0202] The compositions and results are shown in Tables 1 to 5 below.

[0203]

[0204]

[0205]

[0206]

[0207]

[0208] 11... Multilayer printed wiring board 12... Circuit board 12a... Upper surface 13 to 16... Insulating layers 17... Metal layer

Claims

1. It comprises a thermosetting compound (A) and hollow inorganic particles (B), A resin material in which the root mean square height Rq of the outer surface of the hollow inorganic particles (B) is 2 nm or more.

2. The resin material according to claim 1, wherein the hollow inorganic particles (B) are hollow silica particles.

3. The resin material according to claim 1 or 2, wherein the thermosetting compound (A) includes a thermosetting compound having an epoxy group, a vinyl group, a styryl group, a benzoxazine group, a cyanate group, an allyl group, a methacryloyl group, an acryloyl group, or a maleimide group.

4. The resin material according to claim 1 or 2, wherein the thermosetting compound (A) comprises a maleimide compound.

5. The resin material according to claim 1 or 2, further comprising solid inorganic particles (C).

6. The resin material according to claim 1 or 2, wherein the content of the hollow inorganic particles (B) is 60% by weight or less of 100% by weight of the components excluding the solvent in the resin material.

7. The resin material according to claim 1 or 2, wherein when the resin material is heated at 180°C for 30 minutes and then heated at 200°C for 60 minutes to obtain a cured product of the resin material, the dielectric constant of the obtained cured product at 10 GHz is 2.5 or less.

8. The resin material according to claim 1 or 2, which is a resin film.

9. A resin material according to claim 1 or 2, used for forming an insulating layer in a multilayer printed circuit board.

10. A cured product of a resin material, A cured product wherein the resin material is the resin material described in claim 1 or 2.

11. Circuit board and Multiple insulating layers arranged on the surface of the circuit board, The facility comprises a metal layer disposed between a plurality of insulating layers, A multilayer printed circuit board in which at least one of the plurality of insulating layers is a cured product of the resin material described in claim 1 or 2.