JP2012081586A - Resin sheet, laminated plate, electronic component, print wiring board and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sheet which can be thinned, has both sides having different purposes of use, functions, performances, characteristics or the like, the one side surface having excellent grooving performance and adhesion with a conductive layer and allowing a microcircuit to be formed thereon, and to provide a laminated plate, electronic component, a print wiring board and a semiconductor device produced by using the resin sheet.SOLUTION: The resin sheet has a multilayer structure including a first resin layer forming one surface side and a second resin layer forming the other surface side. The first resin layer contains at least a curable resin, and the second resin layer contains a thermosetting resin and inorganic filler and has a thickness of 5 to 30 μm.

Description

  The present invention relates to a resin sheet, a laminated board, an electronic component, and a printed wiring board semiconductor device.

  With the demand for higher functionality, lighter weight, smaller size, and thinner electronic devices, high density integration and high density mounting of electronic components are progressing. Circuit wiring of printed wiring boards used in these electronic devices tends to have a higher density, and a built-up multilayer wiring structure is employed.

  In recent years, a semi-additive method (SAP method) has begun to be performed as a technique for achieving formation of a fine circuit on a printed wiring board. In the SAP method, a resin surface is desmeared to roughen the surface, an electroless copper plating layer using a palladium catalyst is formed on the surface, a photosensitive resist is formed on the copper plating layer, and exposure and development are performed. After patterning through a process such as the above, a circuit pattern is formed by electrolytic copper plating, and finally the resist is peeled off and the electroless copper plating layer is removed by flash etching to form fine wiring ( For example, see Patent Document 1). When fine wiring is formed by this method, there are problems such as exposure / development accuracy of resist and abnormal plating deposition due to palladium catalyst residue between wiring, and the circuit width / inter-circuit width (L / S) is 10 μm / 10 μm or less. It is difficult to form fine wiring.

  In the semi-additive method, convex wiring is formed on the surface of the resin layer. In a build-up board or a multilayer wiring board, a process of laminating a resin layer is included in the subsequent process, but depending on the resin composition, a problem of resin embedding occurs. In particular, in a fine wiring region having a circuit width / inter-circuit width (L / S) of 10 μm / 10 μm or less, it becomes difficult to ensure insulation reliability when the resin embedding property deteriorates.

  Also, grooves are formed in the resin layer by scribing, plasma, laser, etc., the surface of the resin is desmeared to roughen the surface, and an electroless copper plating layer using a palladium catalyst is formed on the surface. There is a method in which a conductor is formed and finally a conductor plating other than the groove portion is removed by etching to form a circuit (for example, see Patent Documents 2 and 3). However, when the unevenness of the groove side wall surface of the insulating layer becomes large, there is a new problem that accuracy in forming the groove is lowered and it becomes difficult to form fine wiring with L / S of 10 μm / 10 μm or less.

  In addition, in a printed wiring board having a multilayer wiring structure, each layer is thinned. However, in the conventional multilayer printed wiring board, the embedding property for embedding the gap of the circuit wiring is required on one surface of the insulating layer, and the groove is formed on the other surface by forming a groove in the resin layer as described above. It was difficult to obtain an insulating layer material satisfying both characteristics when a groove layer for forming a circuit and adhesion with a conductor layer were required by forming a conductor layer on the substrate. .

JP-A-8-64930 Japanese Patent Laid-Open No. 10-4253 JP 2006-41029 A

The object of the present invention is to cope with thinning, and can provide different uses, functions, performances, characteristics, etc. on both surfaces, and one surface has groove workability and adhesion to a conductor layer. Another object of the present invention is to provide a resin sheet that is excellent in that a fine circuit can be formed on the surface.
Another object of the present invention is to provide a laminate, an electronic component, and a semiconductor device produced using the resin sheet.

The object is achieved by the following inventions (1) to (25).
(1) A resin sheet having a multilayer structure including a first resin layer forming one surface side and a second resin layer forming the other surface side,
The first resin layer includes at least a curable resin,
Said 2nd resin layer contains a thermosetting resin and an inorganic filler, and thickness is 5-30 micrometers, The resin sheet characterized by the above-mentioned.
(2) At least the surface of the first resin layer is coated with a carrier film selected from the group consisting of a polymer film and a copper foil having a 10-point average roughness (Rz) of 4.0 μm or less, The resin sheet as described in 1).
(3) The resin sheet according to (1) or (2), wherein the first resin layer further includes an inorganic filler, and a coarse particle exceeding 2 μm in the inorganic filler is 500 ppm or less.
(4) The resin sheet according to (3), wherein the content of the inorganic filler contained in the first resin layer is 1 to 60% by weight.
(5) The resin sheet according to (3) or (4), wherein the inorganic filler contained in the first resin layer has an average particle diameter of 0.01 to 0.4 μm.
(6) The resin sheet according to any one of (3) to (5), wherein the inorganic filler is spherical silica.
(7) The resin sheet according to (1) or (2), wherein the first resin layer does not include an inorganic filler.
(8) The resin sheet according to any one of (1) to (7), wherein the curable resin included in the first resin layer includes a thermosetting resin and / or a photosensitive resin.
(9) The resin sheet according to (8), wherein the thermosetting resin includes at least one selected from an epoxy resin, a phenol resin, a cyanate resin, and a benzocyclobutene resin.
(10) The second resin layer includes an epoxy resin, an amorphous first inorganic filler, and a second inorganic material having an average particle diameter different from that of the first inorganic filler and an average particle diameter of 10 to 100 nm. The resin sheet according to any one of (1) to (9), including a filler.
(11) The second resin layer comprises an epoxy resin, silicone rubber fine particles having an average particle size of 1 μm to 10 μm, boehmite fine particles having an average particle size of 0.2 μm to 5 μm, and silica nanoparticles having an average particle size of 10 nm to 100 nm. The resin sheet according to any one of (1) to (10) above.
(12) The resin sheet according to any one of (1) to (11), including a base material layer between the first resin layer and the second resin layer.
(13) The resin sheet according to (12), which has a three-layer structure including the first resin layer, the base material layer, and the second resin layer.
(14) The resin sheet according to (12) or (13), wherein the base material used for the base material layer is a glass cloth.
(15) The resin sheet according to any one of (1) to (14), wherein the thickness of the first resin layer is 6 to 28 μm.
(16) The thickness of the first resin layer is 15 to 50% of the total thickness of the thickness of the first resin layer and the thickness of the second resin layer. Resin sheet.
(17) The resin sheet according to any one of (1) to (16), wherein the overall thickness is 60 μm or less.
(18) Only the resin sheet according to any one of (1) to (16) above, or the resin sheet is arranged at the position of the outermost layer on at least one side so that the first resin layer faces the surface side. A laminated board that is laminated.
(19) An insulating layer made of a cured product of the resin sheet according to any one of (1) to (17), a groove provided on a surface of the first resin layer of the insulating layer, and an inside of the groove An electronic component comprising a conductor track structure having a provided conductor layer.
(20) An insulating layer made of a cured product of the resin sheet according to any one of (1) to (17), a groove provided on a surface of the first resin layer of the insulating layer, and an inside of the groove A printed wiring board comprising at least one buildup layer having a provided conductor layer.
(21) The printed wiring board according to (20), wherein the maximum width of the groove is 1 to 10 μm.
(22) The printed wiring board according to (20) or (21), wherein the arithmetic average roughness (Ra) of the surface of the groove in contact with the conductor layer is 0.05 to 0.45 μm.
(23) In the above (20) to (22), the depth of the groove is 2 to 20 μm, and the thickness of the first resin layer is 1.2 to 1.4 times the depth of the groove. The printed wiring board as described in any one.
(24) The height of the conductor circuit covered with the buildup layer is 5 to 20 μm, and the thickness of the second resin layer is 1 to 1.5 times the height of the conductor circuit. 20) The printed wiring board according to any one of (23).
(25) A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to any one of (20) to (24).

The resin sheet of the present invention can cope with thinning, and can impart different uses, functions, performances, characteristics, etc. to both surfaces, and one surface is in close contact with the groove processability and the conductor layer. It is excellent in performance, and a fine circuit can be formed on the surface.
Furthermore, according to the present invention, using the resin sheet, it is possible to obtain a laminated board and an electronic component such as a printed wiring board having high density and excellent connection reliability, and a semiconductor device.

It is sectional drawing which shows typically an example of the resin sheet concerning this invention. It is process drawing which shows an example of the process of manufacturing the resin sheet of this invention. It is sectional drawing which shows typically an example of the printed wiring board of this invention. It is a figure explaining an example of the manufacturing method of the printed wiring board of this invention.

The resin sheet of the present invention is a resin sheet having a multilayer structure including a first resin layer forming one surface side and a second resin layer forming the other surface side,
The first resin layer includes at least a curable resin,
The second resin layer includes a thermosetting resin and an inorganic filler and has a thickness of 5 to 30 μm.

The first resin layer of the present invention contains at least a curable resin, and irregularities on the side wall surface inside the groove after patterning the fine circuit by forming the groove by a laser processing method or a photolithography method are appropriate, Adhesiveness between the first resin layer and the formed conductor layer is increased.
On the other hand, the second resin layer has a composition different from that of the first resin layer, and the second resin layer is designed to have different characteristics (for example, circuit embedding property) from the first resin layer. Yes. Here, the resin layers have different compositions as long as at least one of the types and contents of each component such as resin and inorganic filler contained in each resin layer and the molecular weight of the resin is different. .

Hereinafter, based on FIG. 1, the resin sheet of this invention is demonstrated.
FIG. 1 is a cross-sectional view schematically showing an example of a resin sheet according to the present invention. A resin sheet 100 shown in FIG. 1 includes a first resin layer 1, a second resin layer 2, a carrier film 3 that covers the surface of the first resin layer, a carrier film 4 that covers the surface of the second resin layer, and a substrate. It consists of a material layer 5.

(First resin layer)
First, the first resin layer will be described.
The first resin layer includes at least a curable resin. As the curable resin, a thermosetting resin and / or a photosensitive resin can be used. When the first resin layer contains a thermosetting resin as a main component as a curable resin, the first resin layer can be selectively formed with a groove by a known laser processing method to pattern a fine circuit. It becomes possible. When the first resin layer contains a photosensitive resin as a main component as a curable resin, the first resin layer can be selectively patterned by a well-known photolithography method to pattern a fine circuit. It becomes. In addition, in this invention, the main component of curable resin means the component which occupies 50 weight% or more of the whole curable resin.

Examples of the thermosetting resin include novolak type phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, unmodified resol phenol resin, oil-modified resole phenol modified with tung oil, linseed oil, walnut oil, and the like. Resol type phenol resin such as resin, phenol resin such as biphenyl aralkyl type phenol resin, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol Z type epoxy resin, bisphenol P type epoxy Resin, bisphenol type epoxy resin such as bisphenol M type epoxy resin, novolak type epoxy resin such as phenol novolac type epoxy resin and cresol novolac epoxy resin Xyoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, aryl alkylene type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin Resin, epoxy resin such as fluorene type epoxy resin, resin having triazine ring such as urea (urea) resin, melamine resin, unsaturated polyester resin, maleimide resin, bisallyl nadiimide compound, vinyl benzyl resin, vinyl benzyl ether resin, Polyimide resin, polyamideimide resin, polyurethane resin, diallyl phthalate resin, silicone resin, resin having a benzoxazine ring, triazine resin, benzocyclobutene resin Cyanate resins. Among these, the inclusion of one or more kinds of resins selected from epoxy resins, phenol resins, cyanate resins and benzocyclobutene resins forms fine wiring with high insulation reliability and excellent signal response. To preferred.
When the thermosetting resin is a main component as the curable resin of the first resin layer, among these thermosetting resins, it is preferable to include an epoxy resin, a phenol resin and / or a cyanate resin, In particular, it is preferable to contain a cyanate resin. Thereby, the thermal expansion coefficient of the first resin layer can be reduced. Further, when the cyanate resin is contained, the first resin layer is excellent in electrical characteristics (low dielectric constant, low dielectric loss tangent), mechanical strength, laser workability, particularly excimer laser and YAG laser workability.
In the case where the thermosetting resin and the photosensitive resin are used in combination as the curable resin of the first resin layer, an epoxy resin is included among these thermosetting resins because the heat resistance can be further improved. It is preferable that a phenol resin is further contained from the viewpoint of improving alkali developability.

The cyanate resin is not particularly limited, and can be obtained, for example, by reacting a halogenated cyanide compound with phenols or naphthols, and prepolymerizing by a method such as heating as necessary. Moreover, the commercial item prepared in this way can also be used.
Although it does not specifically limit as a kind of cyanate resin, For example, bisphenol type cyanate resin, such as novolak type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, tetramethylbisphenol F type cyanate resin, naphthol aralkyl type cyanate resin , Biphenyl aralkyl type cyanate resin, dicyclopentadiene type cyanate resin and the like.
The cyanate resin preferably has two or more cyanate groups (—O—CN) in the molecule. For example, 2,2′-bis (4-cyanatophenyl) isopropylidene, 1,1′-bis (4-cyanatophenyl) ethane, bis (4-cyanato-3,5-dimethylphenyl) methane, 3-bis (4-cyanatophenyl-1- (1-methylethylidene)) benzene, dicyclopentadiene type cyanate ester, phenol novolac type cyanate ester, bis (4-cyanatophenyl) thioether, bis (4-cyanato) Phenyl) ether, 1,1,1-tris (4-cyanatophenyl) ethane, tris (4-cyanatophenyl) phosphite, bis (4-cyanatophenyl) sulfone, 2,2-bis (4-si Anatophenyl) propane, 1,3-, 1,4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1, , 6-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, phenol novolac type, cresol novolac type polyhydric phenols, cyanate resin obtained by reaction with cyanogen halide, naphthol aralkyl type polyvalent naphthols And cyanate resin obtained by reaction with cyanogen halide.
Among these, novolac type cyanate resin is preferable. By including the novolac-type cyanate resin, the thermal expansion coefficient of the first resin layer can be reduced, and the mechanical strength and electrical characteristics (low dielectric constant, low dielectric loss tangent) can be improved. Naphthol aralkyl-type cyanate resins and biphenyl aralkyl-type cyanate resins can also be preferably used because they are excellent in low linear expansion, low water absorption, and mechanical strength.

The molecular weight of the cyanate resin is not particularly limited, but is preferably 5.0 × 10 ^{2 to} 4.5 × 10 ³ , and particularly preferably 6.0 × 10 ^{2 to} 3.0 × 10 ³ . When the molecular weight is less than the lower limit, the mechanical strength of the first resin layer may be reduced, and when an insulating layer is formed during production of a printed wiring board or the like, tackiness occurs, and the first resin layer Some may be missing. Further, when the molecular weight exceeds the upper limit, the curing reaction is accelerated, and a molding defect may occur during the production of a printed wiring board or the like.

  Further, although not particularly limited, cyanate resins including derivatives thereof can be used alone, or two or more having different molecular weights can be used together, or one or two or more prepolymers thereof. Can also be used together.

  When a cyanate resin (particularly a novolac-type cyanate resin) is used as the thermosetting resin, it is preferable to use an epoxy resin (substantially free of halogen atoms) in combination.

Although it does not specifically limit as an epoxy resin, For example, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol Z type epoxy resin, bisphenol P type epoxy resin, bisphenol M type epoxy resin Bisphenol type epoxy resin, phenol novolac type epoxy resin, cresol novolac epoxy resin, etc. novolac type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, arylalkylene type epoxy resin such as biphenyl aralkyl type epoxy resin, naphthalene type epoxy, etc. Resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, Adamantane type epoxy resins and fluorene type epoxy resins and the like.
One of these may be used alone, or two or more having different molecular weights may be used in combination, or two or more of the above epoxy resins and their prepolymers may be used in combination.

  Among these epoxy resins, aryl alkylene type epoxy resins are particularly preferable. Thereby, moisture absorption solder heat resistance and a flame retardance can be improved. The aryl alkylene type epoxy resin refers to an epoxy resin having one or more aryl alkylene groups in a repeating unit. For example, xylylene type epoxy resin, anthracene type epoxy resin, biphenyl dimethylene type epoxy resin, naphthalene dimethylene type epoxy resin, naphthalene modified cresol novolac epoxy resin and the like can be mentioned. Among these, biphenyl dimethylene type epoxy resins, naphthalene-modified cresol novolac epoxy resins, anthracene type epoxy resins, and naphthalene dimethylene type epoxy resins are preferable. A naphthol aralkyl type epoxy resin and a dicyclopentadiene type epoxy resin can also be preferably used because of low linear expansion, low water absorption, and excellent mechanical strength.

The molecular weight of the epoxy resin, is not particularly limited, preferably ^{5.0 × 10 2 ~2.0 × 10 4} , especially 8.0 × ¹⁰ 2 ~1.5 × ^{10 4} are preferable. When the insulating layer is formed during the production of a printed wiring board or the like when the molecular weight is less than the lower limit value, tackiness may occur and a part of the first resin layer may be lost. Solder heat resistance of a board or the like may be reduced. By setting the molecular weight within the above range, it is possible to achieve an excellent balance of these characteristics.

The said thermosetting resin can be used 1 type or in combination of 2 or more types. When the photosensitive resin is not included as the first layer curable resin and only the thermosetting resin is used, it is usually used as a thermosetting resin in combination with a curing agent. When a thermosetting resin and a photosensitive resin are used in combination as the curable resin of the first resin layer, the heat resistance of the first resin layer can be improved by including the thermosetting resin.
Although content of the said thermosetting resin is not specifically limited when the said curable resin has thermosetting resin as a main component, it is 20 to 90 weight% on the basis of solid content in a 1st resin layer, Furthermore, 30 -80% by weight is preferable, and 40-70% by weight is particularly preferable. If the content is less than the lower limit, it may be difficult to form the first resin layer, and if the content exceeds the upper limit, the strength of the first resin layer may be reduced.
The content of the thermosetting resin is not particularly limited when the curable resin is mainly composed of a photosensitive resin, but is preferably 10 to 40% by weight based on the solid content in the first resin layer, and particularly 15 to 35% by weight is preferred. If the content is less than the lower limit, the effect of improving heat resistance may be reduced, and if the content exceeds the upper limit, the effect of improving toughness may be reduced. Therefore, the resin composition excellent in both balance can be obtained by making content of a thermosetting resin into the said range.

  In the case of a laser processing method, it is preferable that the first resin layer further contains a thermoplastic resin. Thereby, the improvement of the mechanical strength of the insulating resin layer obtained, the plating adhesion with the conductor circuit is improved, and the moisture resistance reliability can be improved.

Examples of the thermoplastic resin include polyimide resins, polyamideimide resins, polyphenylene oxide resins, polyethersulfone resins, polyester resins, polyethylene resins, polyvinyl acetal resins, polystyrene resins and other thermoplastic resins, styrene-butadiene copolymers, styrene-isoprene. Polystyrene thermoplastic elastomers such as copolymers, polyolefin thermoplastic elastomers, thermoplastic elastomers such as polyamide elastomers and polyester elastomers, diene elastomers such as polybutadiene, epoxy modified polybutadiene, acrylic modified polybutadiene, and methacrylic modified polybutadiene The present invention is not limited to these at all. They can be used alone, or two or more kinds having different weight average molecular weights can be used in combination, or one kind or two or more kinds and a prepolymer thereof can be used in combination. Among these, it is preferable to use one selected from polyvinyl acetal resin, polyimide resin, polyamide resin, polysulfone resin, polyethersulfone resin, and phenoxy resin. Thereby, plating adhesion, mechanical strength, heat resistance, and chemical resistance can be further improved.

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

  Specific examples of the polyimide resin include polyimide “Rika Coat SN20” and “Rika Coat PN20” manufactured by Shin Nippon Rika Co., Ltd. Moreover, modified polyimides, such as a polybutadiene modified polyimide and a polysiloxane skeleton containing polyimide, are mentioned. Specific examples of the polyamideimide resin include polyamideimides “Bilomax HR11NN” and “Bilomax HR16NN” manufactured by Toyobo Co., Ltd. In addition, modified polyamideimides such as polysiloxane skeleton-containing polyamideimides “KS9100” and “KS9300” manufactured by Hitachi Chemical Co., Ltd. may be mentioned. Specific examples of the polyethersulfone resin include polyethersulfone “PES5003P” manufactured by Sumitomo Chemical Co., Ltd. Specific examples of the polysulfone resin include polysulfone “P1700” and “P3500” manufactured by Solven Advanced Polymers Co., Ltd. Further, acrylonitrile such as “BPAM-01” and “BPAM-155” manufactured by Nippon Kayaku Co., Ltd. and / or polybutadiene-modified polyamide may be mentioned. These various thermoplastic resins may be used in combination of two or more.

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton And those having one or more skeletons selected from trimethylcyclohexane skeletons. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Examples of commercially available phenoxy resins include 1256, 4250 (bisphenol A skeleton-containing phenoxy resin) manufactured by Japan Epoxy Resin Co., Ltd., YX8100 (bisphenol S skeleton-containing phenoxy resin) manufactured by Japan Epoxy Resin Co., Ltd., Japan Epoxy Resin ( YX6954 (bisphenol acetophenone skeleton-containing phenoxy resin) manufactured by Co., Ltd., FX280, FX293 manufactured by Toto Kasei Co., Ltd., YL7553BH30, YL6794, YL7213, YL7290, YL7482 manufactured by Japan Epoxy Resins Co., Ltd. and the like can be mentioned.

Although it does not specifically limit as said photosensitive resin, It is preferable that an alkali-soluble photosensitive resin is included, and it is especially preferable that an alkali-soluble photosensitive resin and a photopolymerizable compound are included.
By using a resin containing an alkali-soluble group as the photosensitive resin, when removing the unreacted resin in the double bond portion during the development process, instead of an organic solvent usually used as a developer, the burden on the environment is reduced. Less alkaline aqueous solution can be applied and the heat resistance of the first resin layer can be maintained because the double bond portion contributes to the curing reaction.

  Examples of the alkali-soluble photosensitive resin include cresol type, phenol type, bisphenol A type, bisphenol F type, catechol type, resorcinol type, pyrogallol type novolak resin, phenol aralkyl resin, hydroxystyrene resin, methacrylic acid resin, methacrylic resin, and the like. An acrylic resin such as an acid ester resin, a cyclic olefin resin containing a hydroxyl group, a carboxyl group, or the like, or a polyamide resin (specifically, having at least one of a polybenzoxazole structure and a polyimide structure, and having a main chain or a side chain Resin having a hydroxyl group, a carboxyl group, an ether group or an ester group, a resin having a polybenzoxazole precursor structure, a resin having a polyimide precursor structure, a resin having a polyamic acid ester structure, and the like.

The alkali-soluble photosensitive resin is more preferably a resin having an alkali-soluble group and a double bond.
Examples of the resin having an alkali-soluble group and a double bond include a curable resin that can be cured by both light and heat.
Examples of the alkali-soluble group include a hydroxyl group and a carboxyl group. This alkali-soluble group can also contribute to the thermosetting reaction.
Examples of such resins include thermosetting resins having photoreactive groups such as acryloyl groups, methacryloyl groups, and vinyl groups, and thermal reactive groups such as phenolic hydroxyl groups, alcoholic hydroxyl groups, carboxyl groups, and acid anhydride groups. And a photo-curable resin. The photocurable resin may further have a heat reactive group such as an epoxy group, an amino group, or a cyanate group. Specific examples include (meth) acryl-modified phenolic resins, (meth) acryloyl group-containing acrylic acid polymers, carboxyl group-containing (epoxy) acrylates, and the like. Further, a thermoplastic resin such as a carboxyl group-containing acrylic resin may be used. Among these, a (meth) acryl-modified phenol resin is preferable.

  When a thermosetting resin having a photoreactive group is used as the alkali-soluble photosensitive resin, the modification rate (substitution rate) of the photoreactive group is not particularly limited, but the reaction of the resin having the alkali-soluble group and the double bond 20 to 80% of the whole group is preferable, and 30 to 70% is particularly preferable. By setting the modified amount of the photoreactive group in the above range, the resolution is particularly excellent.

  On the other hand, when using a photocurable resin having a thermally reactive group as the alkali-soluble photosensitive resin, the modification rate (substitution rate) of the thermally reactive group is not particularly limited, but the resin having the alkali-soluble group and the double bond 20 to 80% of the whole reactive group is preferable, and 30 to 70% is particularly preferable. By setting the modification amount of the thermal reactive group within the above range, the resolution is particularly excellent.

The weight average molecular weight of the resin having an alkali-soluble group and a double bond is not particularly limited, but is preferably 30,000 or less, particularly preferably 5,000 to 150,000. When the weight average molecular weight is within the above range, the film forming property when forming the first resin layer is particularly excellent.
Here, the weight average molecular weight can be evaluated using, for example, GPC (gel permeation chromatography), and the weight average molecular weight can be calculated from a calibration curve prepared in advance using a styrene standard substance. In addition, it can measure on 40 degreeC temperature conditions, using tetrahydrofuran (THF) as a measurement solvent.

  The content of the alkali-soluble photosensitive resin is not particularly limited, but is preferably 15 to 50% by weight, particularly preferably 20 to 40% by weight based on the solid content of the entire first resin layer. In particular, it may be 10 to 80% by weight, preferably 15 to 70% by weight, of the resin components of the first resin layer (all components except the inorganic filler). If the content of the alkali-soluble photosensitive resin is less than the lower limit, the effect of improving the compatibility with the photocurable resin and the thermosetting resin may be reduced. If the content exceeds the upper limit, developability or photo In some cases, the resolution of patterning by the lithography method is lowered. By making content of alkali-soluble photosensitive resin into said range, after patterning resin by the photolithographic method, the adhesiveness of the conductor layer formed in the inside of a groove | channel can be improved.

  When an alkali-soluble photosensitive resin is used as the photosensitive resin, it is preferable to use a photopolymerizable compound in combination. Thereby, patternability can be improved more with the alkali-soluble photosensitive resin mentioned above.

  The photopolymerizable compound is not particularly limited, and examples thereof include glycerin dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. Can be mentioned.

Among such photopolymerizable compounds, a bifunctional or higher functional photopolymerizable compound is preferable, and a trifunctional or higher functional second photopolymerizable compound is particularly preferable. Thereby, even if it is a case where an inorganic filler is not included substantially, it is excellent in the shape retainability of the 1st resin layer. This is presumably because photocrosslinking occurs three-dimensionally, the photocrosslinking density increases, and the thermal elastic modulus does not decrease.
Examples of such a tri- or higher functional photopolymerizable compound include trimethylolpropane trimethacrylate and pentaerythritol triacrylate.

  Here, although content of the said photopolymerizable compound is not specifically limited, 5 to 50 weight% is preferable on the solid content basis of the whole said 1st resin layer, and 10 to 40 weight% is especially preferable. When the content exceeds the upper limit, the adhesion strength with the second resin layer or the base material layer may be lowered, and when the content is less than the lower limit, the shape retainability may be lowered.

The first resin layer may or may not contain an inorganic filler. When said 1st resin layer contains an inorganic filler, it is preferable that the coarse particle exceeding 2 micrometers is 500 ppm or less. Since the first resin layer of the present invention contains an inorganic filler, it has low thermal expansion, high elasticity, and low water absorption when used as an insulating layer for electronic components such as multilayer printed wiring boards, semiconductor elements, and metal core wiring boards. , Mounting reliability and warpage are improved. In addition, since the inorganic filler that fulfills such a function has a coarse particle exceeding 2 μm of 500 ppm or less, the insulating layer in the portion made of the first resin layer is formed with a groove by a laser processing method or a photolithography method. In the patterning of fine circuits, the circuit width / inter-circuit width (L / S) is excellent in groove workability of 10 μm / 10 μm or less, and it is possible to suppress the unevenness of the side wall surface inside the groove from becoming too large. . It is preferable that the unevenness of the side wall surface inside the groove is appropriate from the viewpoint of excellent adhesion between the groove formed in the insulating layer and the conductor layer formed in the groove. On the other hand, since the coarse grain content that adversely affects the unevenness while including the inorganic filler is specified, the unevenness of the side wall surface inside the groove after the groove processing becomes appropriate, the insulating layer and the formed conductor layer and An insulating layer having high adhesion can be formed.
Moreover, the unevenness | corrugation of the insulating layer side wall surface inside the groove | channel which touches a conductor layer is reflected in the unevenness | corrugation of the conductor layer surface inside a groove | channel. According to the present invention, since the surface unevenness of the conductor layer formed inside the groove is reduced, transmission loss due to the skin effect can be reduced in a high frequency region exceeding 1 GHz, and a fine wiring for high frequency can be formed. A high frequency signal causes signal propagation on the surface of the conductor layer. However, if the surface irregularity of the conductor layer is too large, the transmission distance is extended, so that transmission is delayed or loss during propagation is increased.
The inorganic filler preferably further has a coarse particle exceeding 2 μm in an amount of 300 ppm or less, and particularly a coarse particle exceeding 2 μm in an amount of 5 ppm or less. Thereby, the first resin layer is further excellent in groove workability and adhesiveness with the conductor layer.
In addition, the method of obtaining the inorganic filler whose coarse particle over 2 micrometers is 500 ppm or less is not specifically limited. For example, as a method of removing coarse particles exceeding 2 μm, in a slurry state in an organic solvent and / or water, coarse particles are removed several times with a pore size filter having an average particle size of 10 times or more, and then a pore size of 2 μm. It can be obtained by repeatedly removing coarse particles exceeding 2 μm with a filter.

  The coarse particle size and content of the inorganic filler can be measured with a particle image analyzer (FPIA-3000S manufactured by Sysmex Corporation). The inorganic filler can be dispersed by ultrasonic waves in water or an organic solvent, and the number of inorganic fillers exceeding 2 μm can be calculated and measured from the obtained image. Specifically, the content is defined by the number of particles exceeding 2 μm in the equivalent circle diameter of the inorganic filler and the total number of analyzed particles.

  The maximum particle size of the inorganic filler is preferably 2.0 μm or less. Thereby, it becomes easy to realize the surface roughness of the specified first resin layer, and it is possible to form fine wiring with high insulation reliability and excellent signal response. Although not particularly limited, the maximum particle size of the inorganic filler is more preferably 1.8 μm or less, and particularly preferably 1.5 μm or less. Thereby, the effect | action which improves insulation reliability, signal responsiveness, the plating property in a groove | channel, and interlayer connection reliability can be expressed effectively.

  Moreover, as an average particle diameter of the said inorganic filler, it is preferable that it is 0.01-0.4 micrometer. Thereby, it becomes easy to realize fine wiring formation with high insulation reliability and excellent signal response. When the average particle size of the inorganic filler is in the above range, the groove processing property for forming fine wiring with a circuit width / inter-circuit width (L / S) of 10 μm / 10 μm or less is excellent by a laser processing method. Thus, the surface roughness of the specified resin layer can be easily realized. The average particle size of the inorganic filler is particularly preferably 0.02 to 0.20 μm. Thereby, the effect | action which improves insulation reliability, signal responsiveness, the plating property in a groove | channel, and interlayer connection reliability can be expressed effectively.

  The average particle diameter of the inorganic filler can be measured, for example, by a laser diffraction scattering method or a dynamic light scattering method. Disperse the inorganic filler with ultrasonic waves in water, and fill it with a laser diffraction particle size distribution measuring device (HORIBA, LA-500) or a dynamic light scattering particle size distribution measuring device (HORIBA, LB-550). It can be measured by creating a particle size distribution of the material on a volume basis and setting its median diameter (D50) as the average particle diameter.

  When the amount of coarse particles exceeding 2 μm of the inorganic filler exceeds the upper limit, the inorganic filler inhibits laser processing, resulting in a location where grooves cannot be formed in the first resin layer, or the groove shape becomes distorted. There is a possibility that the resin may crack, and there is a possibility that the insulation reliability and the plating property due to the drop of the coarse filler are lowered. Furthermore, since the time for forming the groove with the laser beam becomes longer, there is a possibility that the workability is lowered. Moreover, the surface unevenness | corrugation of the conductor layer after plating becomes large with the inorganic filler which remained on the groove | channel side wall surface after laser processing. As a result, the accuracy of circuit wiring deteriorates, and insulation reliability may be impaired in a high-density printed wiring board. Furthermore, in a high frequency region exceeding 1 GHz, signal responsiveness may be impaired due to the skin effect. Even if the average particle size of the inorganic filler exceeds the upper limit, there is a similar possibility.

  In addition, if the average particle size of the inorganic filler is less than the lower limit, the physical properties of the thermal expansion coefficient and elastic modulus of the first resin layer may be lowered, and the mounting reliability when mounting the semiconductor element may be impaired. Moreover, the dispersibility of the inorganic filler in the first resin layer and the occurrence of aggregation may occur, or it may be difficult to form a resin film due to a decrease in flexibility in the B-stage state of the first resin layer.

  The inorganic filler is not particularly limited. For example, talc, fired clay, unfired clay, mica, glass and other silicates, titanium oxide, alumina, silica, fused silica and other oxides, carbonic acid Carbonates such as calcium, magnesium carbonate and hydrotalcite, hydroxides such as aluminum hydroxide, magnesium hydroxide, boehmite and calcium hydroxide, sulfates or sulfites such as barium sulfate, calcium sulfate and calcium sulfite, boric acid Borate salts such as zinc, barium metaborate, aluminum borate, calcium borate and sodium borate, nitrides such as aluminum nitride, boron nitride, silicon nitride and carbon nitride, titanic acid such as strontium titanate and barium titanate A salt etc. can be mentioned. As the inorganic filler, one of these can be used alone, or two or more can be used in combination. Among these, silica is preferable and fused silica is more preferable in terms of excellent low thermal expansion, flame retardancy, and elastic modulus. Among these, the shape is preferably spherical silica.

  The content of the inorganic filler is 1 to 60% by weight based on the solid content of the entire first resin layer, more preferably 5 to 50% by weight, and particularly 10 to 40% by weight. This is preferable because it is possible to form a fine wiring with high reliability and excellent signal response.

  Further, the first resin layer can improve the uniform dispersibility of the inorganic filler and can uniformly roughen the side wall surface inside the groove when processing the groove for forming fine wiring by a laser processing method. From the viewpoint, it is preferable to include a coupling agent. Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent. Examples of the silane coupling agent include N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3- (2-aminoethyl) aminopropyltrimethoxysilane. 3- (2-aminoethyl) aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-anilinopropyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -3-aminopropyl Aminosilane compounds such as trimethoxysilane and N-β- (N-vinylbenzylaminoethyl) -3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane and 2 -(3,4-epoxy Cyclohexyl) epoxysilane compounds such as ethyltrimethoxysilane, and others include 3-mercatopropyltrimethoxysilane, 3-mercatopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, and Examples include 3-methacryloxypropyltrimethoxysilane. From the viewpoint of close contact with the curable resin, epoxy silane, amino silane and the like are preferably used.

Moreover, the 1st resin layer of this invention may contain the photoinitiator further, when the said curable resin contains the said photosensitive resin. Thereby, patterning property can be improved more.
Examples of such a photopolymerization initiator include benzophenone, acetophenone, benzoin, benzoin isobutyl ether, methyl benzoin benzoate, benzoin benzoic acid, benzoin methyl ether, benzylfinyl sulfide, benzyl, dibenzyl, diacetyl and the like.

  Although content of the said photoinitiator is not specifically limited, 0.5-5 weight% is preferable on the solid content basis of the said 1st resin layer whole, and 1-3 weight% is especially preferable. When the content of the photopolymerization initiator is less than the lower limit, the effect of initiating photopolymerization may be reduced. When the content exceeds the upper limit, the reactivity becomes too high, and the first resin material before the resin sheet is produced. And the resolution after patterning of the first resin layer may deteriorate. Therefore, the 1st resin layer excellent in both balance can be provided by making a photoinitiator into said range.

In the production of the resin sheet of the present invention, when the first resin layer is formed, a varnish (first resin varnish) in which a first resin material composed of components constituting the first resin layer is dissolved in a solvent is used. Used.
The solvent is not particularly limited, but a solvent that exhibits good solubility in the resin composition is preferable. For example, acetone, methyl ethyl ketone (MEK), cyclohexanone (ANON), methyl isobutyl ketone (MIBK), cyclopenta Non, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like can be mentioned. In addition, you may use a poor solvent in the range which does not exert a bad influence.

  The nonvolatile content of the first resin varnish is not particularly limited, but is preferably 30 to 80% by weight, and particularly preferably 40 to 70% by weight. Thereby, the impregnation property to the base material of a 1st resin material can be improved.

  As long as the first resin layer does not impair the effects of the present invention, a curing accelerator, a pigment, a dye, an antifoaming agent, a leveling agent, an ultraviolet absorber, a foaming agent, an antioxidant, a flame retardant, You may contain additives other than the said components, such as an ion-trapping agent.

The thickness of the first resin layer is preferably 6 to 28 m, particularly preferably 6 to 21 μm, and more preferably 6 to 14 μm.
The thickness of the first resin layer is preferably equal to or greater than the lower limit for improving insulation reliability, and is preferably equal to or smaller than the upper limit for achieving thinning of the multilayer printed wiring board. If the thickness of the first resin layer is less than the lower limit, the groove may penetrate the first resin layer when the groove is processed. When the resin sheet has a base material layer and the groove reaches the base material layer, when a conductor layer is formed in the groove, electricity is conducted to the base material layer, resulting in poor insulation reliability. Moreover, when a resin sheet does not have a base material layer, a groove | channel processability will worsen when a groove | channel reaches even the 2nd resin layer. On the other hand, if the thickness of the first resin layer exceeds the upper limit, it is difficult to reduce the thickness of the entire resin sheet, and it is difficult to reduce the thickness of the resulting multilayer printed wiring board.

(Second resin layer)
Next, the second resin layer will be described.
Said 2nd resin layer consists of 2nd resin containing a thermosetting resin and an inorganic filler, and thickness is 5-30 micrometers.
The second resin layer has a composition different from that of the first resin layer, and the second resin layer is designed to have different characteristics (for example, circuit embedding property) from the first resin layer.

  The second resin layer is not particularly limited, but the epoxy resin, the amorphous first inorganic filler, and the first inorganic filler are different in average particle diameter and the average particle diameter is 10 to 100 nm. 2 The second resin composition (A) containing an inorganic filler, or an epoxy resin, silicone rubber fine particles having an average particle size of 1 μm to 10 μm, boehmite fine particles having an average particle size of 0.2 μm to 5 μm, and an average particle size It is preferable to consist of a 2nd resin composition (B) containing a 10 nm-100 nm silica nanoparticle.

First, the second resin composition (A) will be described in detail.
In the second resin composition (A), the amorphous first inorganic filler and the second inorganic filler (for example, nano silica) are attracted by an interaction due to a difference in surface potential. Therefore, the second inorganic filler is present around the irregular first inorganic filler, and the second inorganic filler exhibits an action as a spacer of the irregular first inorganic filler. As a result, the attractive force due to the van der Waals force acting between the irregular first inorganic fillers is reduced, and aggregation thereof is prevented. Thereby, the amorphous first inorganic filler is contained in the second resin composition (A) in a highly dispersed state, and a decrease in fluidity of the varnish is suppressed.

The second resin composition (A) of the present invention contains an amorphous first inorganic filler, so that the second resin layer (A) obtained by using the second resin composition (A) has low thermal expansion and heat resistance. And drilling workability can be improved.
Examples of the amorphous first inorganic filler include crushed silica, zinc borate, talc, aluminum hydroxide, boehmite (alumina monohydrate obtained by modifying gibbsite), and the like.
Among these, aluminum hydroxide and boehmite are preferable. It is because the heat resistance and drilling workability of the second resin layer obtained using the second resin composition (A) can be further improved.

The average particle diameter of the first inorganic filler is not particularly limited, but is preferably 0.3 to 5 μm, particularly preferably 0.5 to 5 μm, and more preferably 0.5 to 3 μm. When the average particle size is within the above range, a resin composition that is particularly excellent in the high filling property and fluidity of the first inorganic filler can be obtained.
The average particle diameter of the first inorganic filler can be measured by a laser diffraction scattering method. The inorganic filler is dispersed in water by ultrasonic waves, and the particle size distribution of the inorganic filler is created on a volume basis by a laser diffraction type particle size distribution measuring device (HORIBA, LA-500), and the median diameter (D50) is averaged. It can measure by setting it as a particle diameter.

  Although content of the said 1st inorganic filler is not specifically limited, It is preferable that it is 20 to 65 weight% on the solid content basis of said 2nd resin composition (A) whole, and it is especially 25 to 55 weight%. It is preferable. When the content is in the above range, the balance between heat resistance and fluidity is particularly excellent.

  The 1% thermal decomposition temperature of the first inorganic filler is preferably 260 ° C. or higher, and particularly preferably 300 ° C. or higher. The 1% pyrolysis temperature is defined by a differential thermal balance (TG / DTA) at a temperature increase rate of 10 ° C./min and a temperature at a point of 1% weight reduction from the initial weight. Examples of the first inorganic filler having a 1% thermal decomposition temperature of 300 ° C. or higher include boehmite.

The second resin composition (A) includes a second inorganic filler having an average particle diameter different from that of the first inorganic filler and an average particle diameter of 10 to 100 nm. Thereby, the fall of the fluidity | liquidity of the varnish which arises when using the said 1st non-morphic inorganic filler can be suppressed.
Examples of the second inorganic filler include fused silica obtained by a dry method such as a combustion method and sol-gel silica obtained by a wet method such as a precipitation method and a gel method.

Since the dispersibility of the second inorganic filler material can be improved and the fluidity reduction of the varnish can be further suppressed, the first resin composition is prepared by dispersing a slurry in which the second inorganic filler is previously dispersed in an organic solvent. It is preferable to be prepared using. In particular, it is preferable to use a slurry in which nano-sized silica is previously dispersed in an organic solvent.
By using a slurry in which such a second inorganic filler (especially silica) is previously dispersed in an organic solvent, a decrease in varnish fluidity that occurs when using an amorphous first inorganic filler is suppressed. The reason for this can be considered as follows. First, nano-sized particles such as nano-sized silica tend to aggregate and often form secondary aggregates when blended into the resin composition. Such secondary agglomeration can be prevented, thereby preventing the fluidity from being lowered. Next, aggregation prevention of the amorphous first inorganic filler due to the difference between the surface potential of the second inorganic filler (nano-sized silica) and the surface potential of the amorphous first inorganic filler described above. This is because the effect is enhanced.

The average particle diameter of the second inorganic filler is particularly preferably 15 to 90 nm, and most preferably 25 to 75 nm. When the average particle diameter is within the above range, the high filling property of the second inorganic filler and the high fluidity of the varnish in the second resin composition (A) can be improved.
The average particle diameter can be measured by, for example, an ultrasonic vibration current method (zeta potential), an ultrasonic attenuation spectroscopy (particle size distribution), a laser diffraction scattering method, or a dynamic light scattering method.
For example, an inorganic filler is dispersed in water by ultrasonic waves, and a particle size distribution of the inorganic filler is created on a volume basis by a dynamic light scattering particle size distribution device (manufactured by HORIBA, LB-550). ) As the average particle diameter.

  The content of the second inorganic filler is not particularly limited, but is preferably 0.5 to 20% by weight, particularly preferably 1 to 10% by weight based on the solid content of the entire second resin composition (A). Furthermore, 0.5 to 5 weight% is preferable. When the content is in the above range, the impregnation property of the second resin composition (A) into the substrate is particularly excellent, and the moldability and circuit embedding property of the second resin layer are excellent.

  The weight ratio (w2 / w1) between the content (w1) of the first inorganic filler and the content (w2) of the second inorganic filler is not particularly limited, but is 0.02 to 0.5. It is preferable to be 0.06 to 0.4. When the weight ratio is within the above range, the moldability can be particularly improved.

  Although a 2nd resin composition (A) is not specifically limited, It is preferable that a 3rd inorganic filler with an average particle diameter of 0.2-3 micrometers is included. The second resin layer obtained using the second resin composition (A) by using the third inorganic filler having the average particle diameter together with the first inorganic filler and the second inorganic filler. Heat resistance and dimensional stability can be particularly improved. Further, by using a combination of the first inorganic filler, the second inorganic filler, and the third inorganic filler, a submicron-order inorganic filler such as the third inorganic filler and a non-reactive material such as the first filler are used. Compared with a conventional resin composition in combination with a fixed inorganic filler, the impregnation property with respect to the substrate can be improved, and further, the circuit embedding property of the second resin layer can be improved.

The average particle diameter of the third inorganic filler is particularly preferably 0.3 to 2.5 μm, and most preferably 0.4 to 1.5 μm. When the average particle diameter is within the above range, particularly high filling of the third inorganic filler in the second resin composition (A) and press molding of a resin sheet or a printed wiring board obtained using the resin composition. And the balance with workability such as drilling can be improved.
The average particle diameter of the third inorganic filler can be measured by a laser diffraction scattering method. Specifically, the average particle diameter of the third inorganic filler can be measured by the same method as that for the first inorganic filler.

  The maximum particle size of the third inorganic filler is not particularly limited, but is preferably 10 μm or less, and particularly preferably 5 μm or less. Thereby, the bit breakage rate at the time of drilling in the production of a printed wiring board or the like can be reduced.

  Examples of the third inorganic filler include silica, titanium oxide, silicon nitride, aluminum nitride, boron nitride, and alumina. Among these, silica is preferable, and spherical fused silica is particularly preferable. This is because such fused silica is excellent in low thermal expansion compared to other inorganic fillers. Moreover, the manufacturing method of the said spherical silica is not specifically limited, It can obtain by a well-known method. Examples of the method for producing the spherical silica include a dry silica method, a wet silica method, and a sol-gel method.

  The weight ratio (w2 / w3) between the content (w2) of the second inorganic filler and the content (w3) of the third inorganic filler is not particularly limited, but is 0.02 to 1.5. It is preferable that it is 0.05-1.2 especially. When the weight ratio is within the above range, the moldability of a printed wiring board or the like when laminating a resin sheet using the second resin composition (A) is particularly excellent.

The specific surface area of the third inorganic filler (especially silica) is not particularly limited, but is preferably 1 m ² / g or more and 250 m ² / g or less. If the specific surface area exceeds the upper limit, the third inorganic fillers are likely to aggregate, and the structure of the second resin composition (A) may become unstable. Moreover, when it is less than the said lower limit, it may be difficult to fill a 3rd inorganic filler in a 2nd resin composition (A). The specific surface area can be determined by the BET method.

  The third inorganic filler (particularly silica) may be used after surface treatment with functional group-containing silanes and / or alkylsilazanes in advance. By performing the surface treatment in advance, aggregation of the third inorganic filler can be suppressed, and silica can be favorably dispersed in the second resin composition (A). Moreover, since the adhesiveness of the surface of an epoxy resin and a 3rd inorganic filler improves, the insulating layer excellent in mechanical strength is obtained.

  Known functional group-containing silanes such as the functional group-containing silanes and / or alkylsilazanes can be used. For example, epoxy silane, styryl silane, methacryloxy silane, acryloxy silane, mercapto silane, N-butylaminopropyltrimethoxysilane, N-ethylaminoisobutyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, N-phenyl- 3-aminopropyltrimethoxysilane, 3- (N-allylamino) propyltrimethoxysilane, (cyclohexylaminomethyl) triethoxysilane, N-cyclohexylaminopropyltrimethoxysilane, N-ethylaminoisobutylmethoxyldiethoxysilane, (phenyl Aminomethyl) methyldimethoxysilane, N-phenylaminomethyltriethoxysilane, N-methylaminopropylmethyldimethoxysilane, vinylsilane, isocyanate sila , It may be mentioned Surufidoshiran, chloropropyl silane, a ureido silane compounds.

  Examples of the alkylsilazanes include hexamethyldisilazane (HMDS), 1,3-divinyl-1,1,3,3-tetramethyldisilazane, octamethyltrisilazane, hexamethylcyclotrisilazane, and the like. it can. Among these, hexamethyldisilazane (HMDS) is preferable as the alkylsilazanes.

  The amount of the functional group-containing silanes and / or alkylsilazanes to be surface-treated in advance on the third inorganic filler (particularly silica) is not particularly limited, but is 0.01% with respect to 100 parts by weight of the third inorganic filler. It is preferable that the amount is not less than 5 parts by weight. More preferably, it is 0.1 to 3 parts by weight. If the content of functional group-containing silanes and / or alkylsilazanes exceeds the upper limit, the insulating layer may crack in the production of printed wiring boards and the like, and if the content is less than the lower limit, the resin component In some cases, the bonding force between the first inorganic filler and the third inorganic filler is reduced.

  The method for surface-treating the third inorganic filler (especially silica) with functional group-containing silanes and / or alkylsilazanes is not particularly limited, but a wet method or a dry method is preferable. The wet method is particularly preferable. When compared with the dry method, the wet method can uniformly treat the surface of the third inorganic filler.

  Although content of the said 3rd inorganic filler (especially silica) is not specifically limited, It is preferable that they are 20 weight% or more and 85 weight% or less on the solid content basis of the 2nd resin composition (A) whole. More preferably, it is 25 to 75 weight%. When the content of the third inorganic filler is less than the lower limit value, the linear thermal expansion coefficient of the cured product of the resin sheet may increase or the water absorption rate may increase. Moreover, when the said upper limit is exceeded, the moldability of a 2nd resin layer may fall by the fall of the fluidity | liquidity of a 2nd resin composition (A). By setting the content of the third inorganic filler within the above range, the linear thermal expansion coefficient of the cured product of the second resin composition (A) can be made 35 ppm or less.

  As an epoxy resin contained in said 2nd resin composition (A), the thing similar to what is used for said 1st resin composition can be used. Among these, at least one selected from the group consisting of a biphenyl dimethylene type epoxy resin, a novolac type epoxy resin, a naphthalene-modified cresol novolak epoxy resin, and an anthracene type epoxy resin is particularly preferable. By using these epoxy resins, the moisture absorption solder heat resistance and flame retardance of the obtained electronic component can be improved.

  Although content of the said epoxy resin is not specifically limited, It is preferable to set it as 5 to 60 weight% on the solid content basis of the 2nd resin composition (A) whole. If the content is less than the lower limit, the curability of the second resin composition (A) may be reduced, or the moisture resistance of the second resin layer obtained using the resin composition may be reduced. . Moreover, when the said upper limit is exceeded, the linear thermal expansion coefficient of a 2nd resin layer may become large, or heat resistance may fall. The content of the epoxy resin is particularly preferably 7 to 50% by weight based on the solid content of the entire second resin composition (A).

The molecular weight of the epoxy resin is not particularly limited, but is preferably 1.0 × 10 ^{2 to} 2.0 × 10 ⁴ . If the molecular weight is less than the lower limit, tackiness may occur on the surface of the second resin layer formed using the second resin composition (A). If the molecular weight exceeds the upper limit, the second resin layer The solder heat resistance of the solder may be reduced. By setting the molecular weight within the above range, it is possible to achieve an excellent balance of these characteristics.

The second resin composition (A) is not particularly limited, but preferably contains a cyanate resin. Thereby, a flame retardance can be improved more.
As said cyanate resin, the thing similar to what is used for said 1st resin composition can be used. Among them, phenol novolac type cyanate resin is excellent in flame retardancy and low thermal expansion, and 2,2′-bis (4-cyanatophenyl) isopropylidene and dicyclopentadiene type cyanate ester are used for controlling crosslink density and moisture resistance. Excellent reliability. In particular, a phenol novolac type cyanate resin is preferred from the viewpoint of low thermal expansion. Furthermore, other cyanate resins may be used alone or in combination of two or more, and are not particularly limited.

  The content of the cyanate resin is not particularly limited, but is preferably 5 to 60% by weight, more preferably 10 to 50% by weight, based on the solid content of the second resin composition as a whole (A). Preferably it is 10 to 40% by weight. When the content is within the above range, the cyanate resin can effectively exhibit heat resistance and flame retardancy. When the content of the cyanate resin is less than the lower limit, thermal expansibility increases and the heat resistance may decrease. When the content exceeds the upper limit, the strength may decrease.

  The second resin composition (A) is not particularly limited, but preferably contains a coupling agent. Thereby, the mechanical strength of the 2nd resin layer obtained using a 2nd resin composition (A) can be improved. As said coupling agent, the thing similar to what is used for said 1st resin composition can be used.

In the second resin composition (A), particularly when boehmite is used as the first inorganic filler, it is preferable to use aromatic aminosilane as a coupling agent. As a result, the water absorption of the cured product of the second resin composition (A) can be further reduced by the synergistic effect of boehmite and aromatic aminosilane, and the second resin composition (A) obtained using this second resin composition (A). The circuit embedding property of the two resin layers can be improved.
Examples of the aromatic aminosilane include secondary aromatic aminosilanes such as N-phenyl-3-aminopropyltrimethoxysilane, (phenylaminomethyl) methyldimethoxysilane, and N-phenylaminomethyltriethoxysilane, and 3- ( primary aromatic amines such as m-aminophenoxy) propyltrimethoxysilane, p-aminophenyltrimethoxysilane, m-aminophenyltrimethoxysilane, and the like. Among these, secondary aromatic aminosilanes such as N-phenyl-3-aminopropyltrimethoxysilane are preferable.

  The second resin composition (A) can further use a phenolic curing agent. As the phenolic curing agent, known or commonly used phenolic novolac resins, alkylphenol novolac resins, bisphenol A novolac resins, dicyclopentadiene type phenol resins, zyloc type phenol resins, terpene modified phenol resins, polyvinylphenols, etc. Can be used in combination.

  Although the compounding quantity of the said phenol type hardening | curing agent is not specifically limited, The equivalent ratio (phenolic hydroxyl group equivalent / epoxy group equivalent) with an epoxy resin is less than 1.0 and 0.1 or more are preferable. Thereby, the residue of an unreacted phenol type hardening | curing agent disappears and the moisture absorption heat resistance of the 2nd resin layer obtained using a 2nd resin composition (A) improves. Furthermore, when severe moisture absorption heat resistance is required, the equivalent ratio is particularly preferably in the range of 0.2 to 0.5. In addition, the phenolic curing agent not only acts as a curing agent, but can promote curing of a cyanate group and an epoxy group.

  If necessary, the second resin composition (A) can contain additives other than the above components as long as the characteristics are not impaired. Examples of components other than the above components include curing accelerators such as imidazoles, triphenylphosphine, and quaternary phosphonium salts, surfactants such as acrylates, colorants such as dyes, and pigments. .

Next, the second resin composition (B) will be described in detail.
The second resin composition (B) includes an epoxy resin, silicone rubber fine particles having an average particle size of 1 μm to 10 μm, boehmite fine particles having an average particle size of 0.2 μm to 5 μm, and silica nanoparticles having an average particle size of 10 nm to 100 nm. Containing. Thereby, the varnish of the second resin composition (B) can contain a large amount of the three kinds of particles in a low viscosity state. This is because silica nanoparticles having a negative surface zeta potential selectively adhere around boehmite particles having a positive surface zeta potential, and the repulsive force between the silicone rubber fine particles having the same surface zeta potential and the boehmite particles. This is because the varnish has a low viscosity even if it contains a large amount of particles.
In addition, by using the second resin composition (B) having a low viscosity despite containing a large amount of filler particles as described above, the resin sheet of the present invention has the second resin composition. The second resin layer made of the product (B) is excellent in circuit embedding property, and further excellent in flame retardancy, low thermal expansion property, drill workability, and desmear resistance. Moreover, when the resin sheet of this invention has a base material layer, said 2nd resin composition (B) is excellent in the impregnation property to a base material.

  In addition, the laminated board or the printed wiring board using the second resin composition (B) as described above has a large flow due to the low viscosity of the varnish of the second resin composition (B). When the two-resin composition (B) contains silicone rubber fine particles, boehmite particles, and silica nanoparticles in combination, the fluidity of these particles and the resin fluidity are well balanced, and the cushion of silicone rubber fine particles Due to the effect, there is little variation in pressure due to particles, and there are very few surface streaks.

  As said epoxy resin, the thing similar to the epoxy resin contained in said 2nd resin composition (A) can be used.

  The silicone rubber fine particles are not particularly limited as long as they are elastic rubber fine particles formed of organopolysiloxane. For example, the fine particles made of silicone rubber (organopolysiloxane crosslinked elastomer) itself, and the core portion made of silicone rubber are made of silicone resin. And core-shell structured particles coated with. As the silicone rubber fine particles, KMP-605, KMP-600, KMP-597, KMP-594 (manufactured by Shin-Etsu Chemical Co., Ltd.), Trefill E-500, Trefil E-600 (manufactured by Toray Dow Corning Co., Ltd.) Commercial products such as these can be used.

  The silicone rubber fine particles have an average particle diameter of 1 to 10 μm, and are excellent in the impregnation property of the second resin composition (B) into the base material and the circuit embedding property of the second resin layer comprising the resin composition. From 1 to 5 μm is preferable.

  The content of the silicone rubber fine particles is not particularly limited, but is preferably 5 to 50% by weight based on the solid content of the entire second resin composition (B), and is based on the second resin composition (B). From the viewpoint of excellent impregnation into the material and circuit embedding property of the second resin layer made of the resin composition, the content is particularly preferably 10 to 40% by weight.

  The boehmite particles are monohydrates of aluminum oxide, and are AOH-30, AOH-60 (all manufactured by Navaltech Co., Ltd.), granular BMB series, plate-like BMT series, and scale-like BMF series. Commercial products such as (made by Kawai Lime Industry Co., Ltd.) can also be used.

  The boehmite particles have an average particle diameter of 0.2 to 5 μm, and are excellent in the impregnation property of the second resin composition (B) into the substrate and the circuit embedding property of the second resin layer made of the resin composition. From the point, 0.5 to 4 μm is preferable.

  The content of the boehmite particles is not particularly limited, but is preferably 5 to 50% by weight based on the solid content of the entire second resin composition (B), and the base material of the second resin composition (B). In particular, the content is preferably 10 to 40% by weight from the viewpoint of excellent impregnation into and the circuit embedding property of the second resin layer made of the resin composition.

  The silica nanoparticles have an average particle diameter of 10 to 100 nm, and 40 to 100 nm is preferable from the viewpoint of impregnation. This is because if the average particle size is less than 10 nm, the space between the filaments of the substrate cannot be expanded, and if it is greater than 100 nm, it may not be possible to enter between the filaments.

Although it does not specifically limit as said silica nanoparticle, For example, methods, such as combustion methods, such as VMC (Vaporized Metal Combustion) method and PVS (Physical Vapor Synthesis) method, the melting method which flame-melts crushed silica, a sedimentation method, a gel method Can be used. Among these, the VMC method is particularly preferable. The VMC method is a method in which silica powder is formed by putting silicon powder into a chemical flame formed in an oxygen-containing gas, burning it, and then cooling it. In the VMC method, the particle diameter of the silica fine particles to be obtained can be adjusted by adjusting the particle diameter of the silicon powder to be input, the input amount, the flame temperature, and the like.
Commercially available products such as NSS-5N (manufactured by Tokuyama Co., Ltd.), Sicastar 43-00-501 (manufactured by Micromod), Admanano (Admanano Co., Ltd.) (manufactured by Admatechs Co., Ltd.) can also be used.

  Although content of the said silica nanoparticle is not specifically limited, It is preferable that it is 1-10 weight% on the basis of solid content of the 2nd resin composition (B) whole, and it is especially preferable that it is 2-5 weight%. When the content is within the above range, the impregnation property of the second resin composition (B) into the substrate and the circuit embedding property of the second resin layer made of the resin composition are particularly excellent.

  The weight ratio of the content of the silicone rubber fine particles to the content of the silica nanoparticles (weight of the silicone rubber fine particles / weight of the silica nanoparticles) is not particularly limited, but is preferably 1 to 15, and preferably 1 to 10. It is preferable that it is 2-5 especially.

  The weight ratio of the boehmite particle content to the silica nanoparticle content (boehmite particle weight / silica nanoparticle weight) is not particularly limited, but is preferably 1 to 50, and particularly 2 to 20. It is preferable.

  When the weight ratio of the content of the silicone rubber fine particles to the content of the silica nanoparticles and the weight ratio of the boehmite particles to the content of the silica nanoparticles are within the above ranges, the moldability is particularly good. If it is larger or smaller than the above range, solder failure heat resistance and insulation reliability are likely to be lowered due to the generation of voids.

  The average particle diameter of the silicone rubber fine particles, the boehmite particles, and the silica nanoparticles can be measured by, for example, a laser diffraction scattering method and a dynamic light scattering method. For example, the particles are dispersed in water by ultrasonic waves, and the particle size distribution measuring device (manufactured by HORIBA, LA-500) or the dynamic light scattering particle size distribution measuring device (manufactured by HORIBA, LB-550) is used. The particle size distribution is measured on a volume basis, and the median diameter (D50) is defined as the average particle diameter.

  Furthermore, the 2nd resin composition (B) may contain inorganic fillers, such as a silica, aluminum hydroxide, and a talc, in the range which does not impair a characteristic.

  Said 2nd resin composition (B) is cyanate resin contained in said 2nd resin composition (A), phenol type hardening | curing other than said inorganic fillers and epoxy resins, such as said silicone rubber microparticles | fine-particles, boehmite microparticles | fine-particles, and a silica nanoparticle. The same thing as components other than inorganic fillers, such as an agent, and an epoxy resin can be included.

In the production of the resin sheet of the present invention, when the second resin layer is formed, the second resin material comprising the components constituting the second resin layer is used as a solvent in the same manner as when the first resin layer is formed. A dissolved varnish (second resin varnish) is used.
As said solvent, the thing similar to what is used for a 1st resin varnish can be used.
The nonvolatile content contained in the second resin varnish is not particularly limited, but is preferably 30 to 80% by weight, particularly preferably 40 to 70% by weight. Thereby, the impregnation property to the base material of the 2nd resin material can be improved.

  The thickness of the second resin layer is 5 to 30 μm, and particularly preferably 10 to 20 μm. Thereby, the embedding property of the conductor circuit of the inner layer circuit board is excellent, and high insulation reliability can be imparted. In addition, when the support body which laminates | stacks the resin sheet of this invention does not have a convex-shaped conductor circuit, the said 2nd resin layer can be made as thin as possible.

(Carrier film)
In the resin sheet of the present invention, at least the surface of the first resin layer is covered with a carrier film selected from the group consisting of a polymer film and a copper foil having a 10-point average roughness (Rz) of 4.0 μm or less. It is preferable that the surface of the first resin layer and the surface of the second resin layer are covered with the carrier film. The carrier film is used as a protective film for the purpose of preventing foreign matters from being mixed into the resin layer and contamination of the resin layer surface and the like. The surface of the second resin layer is particularly preferably formed by coating with a polymer film. Further, the carrier film covering the surface of the first resin layer is formed by removing the carrier film by etching or the like and then flattening the surface of the first resin layer with no roughening or low roughness. Can be made easy. In the resin sheet 100 of an example of the present invention shown in FIG. 1, the surface of the first resin layer 1 is covered with the carrier film 3 and the surface of the second resin layer 2 is covered with the carrier film 4.

  Examples of the polymer film include thermoplastics having heat resistance such as polyolefin such as polyethylene and polypropylene, polyester such as polyethylene terephthalate and polybutylene terephthalate, release paper such as polycarbonate and silicone sheet, fluorine resin, and polyimide resin. A resin sheet etc. are mentioned. Among these, a sheet made of polyethylene terephthalate is most preferable because it is inexpensive and easy to adjust the peel strength. Thereby, it becomes easy to peel from the insulating layer in the B-stage state or the insulating layer after the heat and pressure lamination with an appropriate strength.

  The copper foil preferably has a 10-point average roughness (Rz) of 4.0 μm or less, and particularly preferably 2.0 μm or less. Thereby, when the said copper foil is laminated | stacked on the surface of the 1st resin layer, the surface of the 1st resin layer which peeled the said copper foil by the etching etc. can be made flat with no roughness or low roughness, and is fine. Wiring processing is easy.

  The thickness of the carrier film is not particularly limited, but it is preferable to use a film having a thickness of 10 to 70 μm because the handleability when producing a resin sheet is good.

(Base material layer)
The resin sheet of the present invention preferably has a base material layer between the first resin layer and the second resin layer, and in particular, 3 composed of the first resin layer, the base material layer, and the second resin layer. It preferably has a layer structure. A resin sheet 100 according to an example of the present invention illustrated in FIG. 1 has a three-layer structure including a first resin layer 1, a base material layer 5, and a second resin layer 2.
When the resin sheet of this invention has a base material layer between the 1st resin layer and the 2nd resin layer, the 1st resin material which comprises a 1st resin layer in the base material used for the said base material layer, and / or Alternatively, the second resin material constituting the second resin layer is impregnated.
Since the resin sheet of the present invention has the base material layer, the strength of the resin sheet can be improved, and the low thermal expansion property is excellent.
The resin sheet of the present invention may have a multilayer structure including an intermediate layer different from the base material layer.

  As the base material used for the base material layer, glass cloth such as glass woven fabric and glass nonwoven fabric, polyamide resin fiber, aromatic polyamide resin fiber, polyamide resin fiber such as wholly aromatic polyamide resin fiber, polyester resin fiber, Synthetic fiber substrate, kraft paper, cotton linter composed of woven or non-woven fabric mainly composed of aromatic polyester resin fiber, polyester resin fiber such as wholly aromatic polyester resin fiber, polyimide resin fiber, fluororesin fiber, etc. Examples thereof include organic fiber base materials such as paper base materials mainly composed of paper, mixed paper of linter and kraft pulp, and the like. Among these, glass cloth is preferable. Thereby, the intensity | strength of a resin sheet can be improved and a thermal expansion coefficient can be made small.

  Examples of the glass constituting such a glass cloth include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, and H glass. Among these, T glass is preferable. Thereby, the thermal expansion coefficient of a glass cloth can be made small and, thereby, the thermal expansion coefficient of a resin sheet can be made small.

  The thickness of the base material used for the base material layer is not particularly limited, but is preferably 30 μm or less, particularly preferably 25 μm or less, and more preferably 20 μm or less. Thereby, a base material layer can be made thin and the whole thickness of a resin sheet can be made thin.

Since the resin sheet of the present invention has the multilayer structure, the amount of resin can be adjusted according to the circuit pattern. Here, a resin sheet in which the first resin layer and the second resin layer have different thicknesses will be described with reference to FIG. In FIG. 1, since the first resin layer is thinner than the second resin layer, the center of the base material layer is disposed above the center line AA (upper side in FIG. 1).
When the resin sheet does not include a base material layer between the first resin layer and the second resin layer, and the first resin layer and the second resin layer have different thicknesses, the center line A-A Thus, the boundary line between the first resin layer and the second resin layer is shifted.
In addition, even if the thickness of the 1st resin layer and the thickness of the 2nd resin layer are the same, the boundary line of the center of a base material layer or a 1st resin layer and a 2nd resin layer has overlapped with centerline AA. Good.

  In the resin sheet of the present invention, since the thickness of the first resin layer and the thickness of the second resin layer can be different, the first resin layer corresponds to the depth of the groove forming the conductor layer, etc. The resin amount can be adjusted, and the second resin layer can adjust the resin amount corresponding to the remaining copper ratio of the conductor circuit of the inner circuit board. Accordingly, since it is not necessary to provide an extra resin layer, the thickness of the resin sheet can be reduced, and the thickness of electronic components such as laminated boards and printed wiring boards obtained by using the resin sheet, the thickness of the semiconductor device can be reduced. It can also be made thinner.

  The thickness of the first resin layer of the resin sheet is preferably 15 to 50% of the total thickness of the first resin layer and the second resin layer, In particular, it is preferably 25 to 50%. When the ratio of the thickness of the first resin layer is within the above range, when the printed wiring board is manufactured, the unevenness of the conductor circuit of the inner circuit board is filled in the second resin layer, and the groove is formed in the first resin layer. An insulating layer for forming a circuit pattern by processing can be formed, and a suitable thickness of the insulating layer can be ensured.

  The thickness of the entire resin sheet of the present invention excluding the carrier film (T0 in FIG. 1) is preferably 60 μm or less, and particularly preferably 25 to 45 μm. When the thickness of the resin sheet excluding the carrier film is 60 μm or less, it is excellent in thinning a printed wiring board obtained using the resin sheet, and the semiconductor device finally obtained can be thinned.

The linear expansion coefficient in the plane direction of the resin sheet of the present invention is not particularly limited, but is preferably 25 ppm or less, and particularly preferably 5 to 20 ppm. When the linear expansion coefficient is within the above range, the crack resistance against repeated thermal shock can be improved.
The linear expansion coefficient in the plane direction can be evaluated by elevating the temperature at 10 ° C./min using, for example, a TMA apparatus (manufactured by TA Instruments).

Next, the manufacturing method of the resin sheet of this invention is demonstrated using FIG.
Although the manufacturing method of the resin sheet of this invention is not specifically limited, For example, the 1st carrier material 1a is manufactured with the method etc. which apply | coat the said 1st resin varnish to the carrier film 3 previously, and the said 2nd resin varnish is used as a carrier film The 2nd carrier material 2a is manufactured by the method of applying to No.4. The first carrier material 1 a and the second carrier material 2 a are arranged on the base 5 so that the resin surface faces the base 5. (FIG. 2 (a)) Next, heat-press lamination is performed, and the base material 5 is impregnated with the first resin material and / or the second resin material. (Fig. 2 (b))
As a method of laminating the first carrier material 1a and the second carrier material 2a to the base material 5, for example, using a vacuum laminator, the first carrier material 1a is superposed from one side of the base material 5 and the other side The second carrier material 2a is overlapped from the side, bonded and sealed with a laminating roll under reduced pressure, and then heated at a temperature equal to or higher than the melting temperature of the non-volatile component in the resin varnish constituting the first and second carrier materials with a hot air dryer. There is a method of heat treatment at a temperature. At this time, since the substrate is kept under the reduced pressure, it can be melt impregnated by capillary action. The other heat treatment method can be carried out using, for example, an infrared heating device, a heating roll device, a flat platen hot platen press device, or the like.

  In addition, as another method for obtaining such a resin sheet 100, (1) a second resin varnish to be the second resin layer 2 is applied to the substrate 5 and is impregnated and dried; The first resin varnish to be the resin layer 1 is applied and dried by a roll coater, a comma coater, or the like to form a B stage, which becomes the resin layer side and the second resin layer 2 to be the first resin layer 1 formed into the B stage. A method of laminating carrier films 3 and 4 on the other resin layer side, respectively, and laminating under heating and pressure; (2) applying a second resin varnish to the substrate 5; A first carrier material 2a is formed by laminating a carrier film 4 on the resin layer side to be the resin layer 2, and the first resin varnish to be the first resin layer 1 is further coated on the carrier film 3 or the like. Prepare carrier material 1a separately, before On the side to be the first resin layer 1 of the first carrier material 1a, by superimposing the second carrier material 2a, there is heating, a method of laminating under pressure.

  Moreover, as a method of obtaining the resin sheet which does not contain a base material layer, the 1st carrier material 1a manufactured by the method etc. which apply | coat the 1st resin varnish to the carrier film 3 previously, and the 2nd resin varnish are used for the carrier film 4 Examples thereof include a method in which the second carrier material 2a produced by a coating method or the like is disposed so that the first resin layer and the second resin layer are on the inner side and press-laminated.

  In addition, the resin sheet of this invention is not limited to the form in which both the 1st resin layer surface and the 2nd resin layer surface are coat | covered with the carrier film, The carrier film is laminated | stacked on the 1st resin layer surface at least. Although it is preferable, both the first resin layer surface and the second resin layer surface may not be covered with the carrier film.

  In the manufacturing method, the thickness of the resin layer to be the first resin layer formed on the first carrier material and / or the resin layer to be the second resin layer formed on the second carrier material is changed, thereby changing the first The thickness of the resin layer and / or the second resin layer can be changed. Thus, the resin sheet of the present invention can easily adjust the thicknesses of the first resin layer and the second resin layer, and as a result, the thickness of the entire resin sheet excluding the carrier film is adjusted to reduce the thickness. be able to.

Further, according to the present invention, there is provided a laminated plate in which only the resin sheet or the resin sheet is arranged and laminated so that the first resin layer faces the surface side at the position of the outermost layer on at least one surface side. Obtainable.
The laminated board of the present invention can be obtained by heating and press-molding a laminated body in which only one resin sheet of the present invention or a plurality of resin sheets are laminated. As long as the laminated body is laminated with the resin sheet of the present invention disposed at least at the position of the outermost layer on the one side so that the first resin layer faces the surface side, The resin sheet of the invention may be used, or a resin sheet that is not the resin sheet of the present invention may be used.
Thus, the laminate of the present invention may be obtained only from the resin sheet of the present invention, but is obtained by using the resin sheet of the present invention and a resin sheet different from the resin sheet of the present invention in combination. It doesn't matter. Furthermore, the resin sheet of the present invention may be obtained by using resin sheets having different overall thickness and / or the ratio of the thickness of the first resin layer and the thickness of the second resin layer.

  Although the temperature to heat is not specifically limited, 120-220 degreeC is preferable and especially 150-200 degreeC is preferable. Although the pressure to pressurize is not particularly limited, 0.5 to 5 MPa is preferable, and 1 to 3 MPa is particularly preferable. Moreover, you may perform post-curing at the temperature of 150-300 degreeC with a high temperature tank etc. as needed.

Furthermore, a metal-clad laminate can be obtained by laminating a metal foil on the surface of the first resin layer on at least one surface side of the laminate and heating and pressing.
A product obtained by forming a predetermined conductor circuit on the metal foil of the metal-clad laminate by etching or the like and blackening the conductor circuit portion can be used as an inner circuit board of a printed wiring board.

Next, an insulating layer made of a cured product of the resin sheet of the present invention, a groove provided on the surface of the first resin layer of the insulating layer, and a conductor path structure having a conductor layer provided inside the groove are provided. The electronic component will be described.
Examples of the electronic component include a printed wiring board, a semiconductor element, and a metal core wiring board. That is, an insulating layer made of a cured product of the resin sheet formed on an inner layer circuit board or a printed wiring board, a groove provided on the surface of the first resin layer of the insulating layer, and provided in the groove A printed wiring board including at least one build-up layer having a conductive layer, an insulating layer made of a cured product of the resin sheet formed on a metal substrate, a groove provided on the surface of the first resin layer of the insulating layer, And a metal core wiring board having a conductor path structure having a conductor layer provided inside the groove, and a semiconductor element having a rewiring composed of the conductor path structure formed on the wafer surface. In addition, as a substrate used for a printed wiring board, a metal substrate used for a metal core wiring board, and a wafer used for rewiring a semiconductor element, a commonly used one can be appropriately selected and used.

The substrate used for the printed wiring board is not particularly limited. For example, a metal foil such as a copper foil is laminated on one or both sides of a base material impregnated or coated with an insulating resin, and heated, pressurized, or the like. The inner layer circuit board which processed and formed the conductor circuit as needed is mentioned. Examples of the base material include glass fiber base materials such as glass woven fabric and glass nonwoven fabric, polyamide resin fibers, aromatic polyamide resin fibers, polyamide resin fibers such as wholly aromatic polyamide resin fibers, polyester resin fibers, and aromatic polyester resin fibers. , Synthetic fiber base materials composed of woven or non-woven fabrics mainly composed of polyester resin fibers such as wholly aromatic polyester resin fibers, polyimide resin fibers, fluororesin fibers, kraft paper, cotton linter paper, linter and craft Examples include organic fiber base materials such as paper base materials mainly composed of pulp mixed paper, etc., and examples of insulating resins include cyanate resins, epoxy resins, benzocyclobutene resins, phenol resins, polyphenylene ether resins, maleimide resins. , Liquid crystal polymer, polyimide resin, polyamide resin, poly Such Doimido resins, singly or include those multiple uses. For example, when a polyimide resin, a liquid crystal polymer, an epoxy resin, or the like used for the flexible substrate is used as the insulating resin, it can be used without including a base material.
The metal substrate used for the metal core wiring board is not particularly limited. For example, copper and copper alloys, aluminum and aluminum alloys, silver and silver alloys, gold and gold alloys, zinc and zinc alloys, nickel and Examples thereof include nickel-based alloys, tin and tin-based alloys, iron and iron-based alloys. A metal having a low linear expansion coefficient such as 42 alloy may also be used.
The wafer used for the rewiring of the semiconductor element is not particularly limited. For example, silicon, germanium, silicon-germanium, silicon carbide, gallium phosphide, aluminum phosphide, gallium nitride, gallium arsenide, aluminum arsenide, Semiconductor materials such as indium phosphide, indium nitride, indium phosphide, gallium indium phosphide, indium arsenide phosphide, zinc sulfide, and zinc oxide can be given.

  Hereinafter, the printed wiring board of the present invention will be described. The printed wiring board of the present invention includes an insulating layer made of a cured resin sheet, a groove provided on the surface of the first resin layer of the insulating layer, and a buildup layer having a conductor layer provided inside the groove. At least one layer.

  FIG. 3 is a cross-sectional view schematically showing an example of the printed wiring board of the present invention. The printed wiring board 200 includes an insulating layer 6 made of a cured product of the resin sheet 100 shown in FIG. A buildup layer 101 having a groove 7 provided on the surface of the resin layer and a conductor layer 8 provided inside the groove is laminated on the inner layer circuit board 9.

The maximum width of the groove is preferably 1 to 10 μm, more preferably 8 μm or less, further preferably 6 μm or less, and particularly preferably 4 μm or less. Thereby, fine wiring processing becomes possible, and the effect of high density and high mounting can be effectively expressed.
The width of the groove means the length of the upper side in the cross section in the direction perpendicular to the longitudinal direction of the groove, and the maximum width of the conductor layer in the groove on the surface of the first resin layer is usually the groove width. It becomes the same as the maximum width.

  In the printed wiring board of the present invention, the depth of the groove is preferably 2 to 20 μm, and the thickness of the first resin layer 1 is 1.2 to 1.4 times the depth of the groove. Is preferred. The depth of the groove is particularly preferably 5 to 15 μm. As a result, the groove is formed without penetrating the first resin layer, which has excellent groove workability, so that the fine wiring can be processed without causing the groove shape to become distorted, and the resin sheet can be made thinner. it can. Moreover, when a buildup layer has a base material layer, a groove | channel does not reach a base material layer and it is excellent in insulation reliability.

  Moreover, it is preferable that the cross-sectional shape of the groove | channel on the insulating layer surface of the printed wiring board of this invention, and the cross-sectional shape of the conductor layer which has the said groove | channel inside are substantially trapezoid shape, bowl shape, or a triangle. As a result, it is possible to form fine wiring with excellent signal response.

In the present invention, the 10-point average roughness (Rz) of the surface of the insulating layer inside the groove in contact with the conductor layer is preferably 6.0 μm or less, and more preferably 4.0 μm or less. Thereby, the insulation reliability of fine wiring can be expressed effectively.
The 10-point average roughness (Rz) of the surface of the insulating layer inside the groove in contact with the conductor layer is reflected in the 10-point average roughness (Rz) of the surface of the conductor layer inside the groove. The 10-point average roughness (Rz) is the sum of the average of 5 points from the maximum peak height between the measurement lengths and the average of 5 points from the maximum valley depth. Can be evaluated. If the 10-point average roughness (Rz) is too large, a portion where the distance between the fine wirings is remarkably shortened due to the maximum convex portion of the conductor layer is generated, which is disadvantageous for insulation and may reduce reliability. .

  In the present invention, the 10-point average roughness (Rz) is defined by JIS B0601. The 10-point average roughness (Rz) of the groove surface formed in the insulating layer can be measured according to JIS B0601, for example, using WYKO NT1100 manufactured by Veeco.

  Moreover, it is preferable that arithmetic mean roughness (Ra) of the surface of the said groove | channel which touches the said conductor layer is 0.05-0.45 micrometer. The arithmetic average roughness (Ra) of the surface of the insulating layer inside the groove in contact with the conductor layer is reflected in the arithmetic average roughness (Ra) of the surface of the conductor layer inside the groove. By optimizing the surface unevenness inside the groove of the insulating layer, the surface unevenness of the conductor layer is reduced while ensuring the adhesion between the insulating layer and the conductor layer, and the skin effect in a high frequency region exceeding 1 GHz. Can reduce transmission loss and form fine wiring for high frequency. A high frequency signal causes signal propagation on the surface of the conductor layer. However, if the surface irregularity of the conductor layer is too large, the transmission distance is extended, so that transmission is delayed or loss during propagation is increased. Although not particularly limited, the arithmetic average roughness (Ra) of the surface of the groove is more preferably 0.05 μm or more and 0.30 μm or less, and is 0.1 μm or more and 0.25 μm or less. Is particularly preferred. As a result, the transmission loss reducing effect in the high frequency region can be effectively exhibited.

  If the arithmetic average roughness (Ra) is less than the above lower limit value, the conductor layer may be peeled off in the solder heat resistance test, the thermal cycle test, etc., and if the upper limit value is exceeded, high speed signal transmission is hindered. Otherwise, electrical reliability may be impaired.

  In the present invention, arithmetic average roughness (Ra) is defined by JIS B0601. The arithmetic mean roughness (Ra) of the groove surface formed in the resin layer can be measured according to JIS B0601, for example, using WYKO NT1100 manufactured by Veeco.

  The conductor layer in the groove is not particularly limited as long as it is a conductor, and is preferably formed by plating. As a conductor layer, it is preferable that metals, such as copper and nickel, are included, for example. In addition, as said conductor layer, you may consist of two or more types of conductor layers.

  In the printed wiring board of the present invention, the height of the conductor circuit of the inner layer circuit board covered with the build-up layer is 5 to 20 μm, and the thickness of the second resin layer is the height of the conductor circuit. It is preferably 1 to 1.5 times. Thereby, since the conductor circuit of the inner layer circuit board is embedded in the second resin layer without penetrating the second resin layer, the printed wiring board of the present invention is excellent in circuit embedding and filled with the irregularities of the conductor layer. An insulating layer can be formed.

  In addition, in the printed wiring board of this invention, what is obtained by using together the resin sheet of this invention and the conventionally used resin sheet different from the resin sheet of this invention may be used. Furthermore, the resin sheet of the present invention may be obtained by using resin sheets having different overall thickness and / or the ratio of the thickness of the first resin layer and the thickness of the second resin layer.

  Next, an example of a method for manufacturing a printed wiring board according to the present invention will be described with reference to FIG. The printed wiring board shown in FIG. 4 uses an inner layer circuit board 9 having a convex conductor circuit 9a and a glass epoxy base material 9b as the inner layer circuit board, and the resin sheet 100 shown in FIG. 1 as the resin sheet. The resin sheet which has the three-layer structure which consists of the 1st resin layer 1, the base material layer 5, and the 2nd resin layer 2 like this, and the 1st resin layer 1 has thermosetting resin as a main component as curable resin Is used.

First, in step (A), the resin sheet 100 ′ from which the carrier film 4 of the resin sheet 100 shown in FIG. 1 has been peeled is arranged so that the second resin layer 2 side is on the inside, and laminated on the inner layer circuit board 9. Thus, the insulating layer 6 is formed.
A method of laminating the resin sheet 100 ′ on the inner circuit board 11 is not particularly limited, and examples thereof include a method of thermocompression bonding the resin sheet to the inner circuit board 9 using a laminator, a vacuum press, or the like.
The resin sheet 100 ′ laminated on the inner layer circuit board 9 is heated and cured as necessary before and / or after the conductor layer is formed on the first resin layer 1 of the resin sheet 100 ′. The insulating resin 6 is formed by curing the functional resin.

Next, by the steps (B) and (C), the first resin layer 1 of the insulating layer 6 is patterned by a laser processing method using the laser beam 10 and the mask 11. The laser beam 10 is applied to the first resin layer 1 through a mask 11 having a circuit pattern.
As the laser beam 10, it is preferable to use an excimer laser or a UV-YAG laser. By using these lasers, the grooves 7 can be formed with high accuracy and shape, and fine wiring can be formed and the density can be increased. Although not particularly limited, the laser wavelength of the excimer laser is more preferably 193 nm and 248 nm, and particularly preferably 193 nm and 248 nm. Thereby, the effect | action which can form the groove | channel 7 with sufficient precision and a shape can be expressed effectively. The wavelength of the UV-YAG laser is preferably 266 nm of the fourth harmonic and 213 nm of the fifth harmonic. If the wavelength is longer than these, there is a possibility that the uniform groove 7 for fine wiring processing cannot be formed.

  The irradiation condition of the laser beam 10 is selected so that a groove inner surface having an arithmetic average roughness (Ra) of the inner surface of 0.05 μm or more and 0.45 μm or less is formed on the surface of the first resin layer 1. Among them, the arithmetic average roughness (Ra) of the inner surface of the groove 7 is more preferably a condition of 0.05 μm or more and 0.30 μm or less, and a condition of 0.1 μm or more and 0.25 μm or less. It is particularly preferred. Thereby, insulation reliability and signal responsiveness can be improved, transmission loss can be reduced, and further, an action that can reduce plating defects and interlayer connection defects in the groove 7 can be effectively expressed.

  In addition, in the manufacturing method of the printed wiring board of this invention, when the said patterning process (C) is performed with the laser beam 10, the process of desmearing with a plasma or a chemical | medical solution is included between a process (C) and a process (D). It is preferable. Thereby, when the groove 7 is formed by the laser beam 10, fine wiring with high electrical reliability can be obtained except for the carbide remaining on the side wall surface of the groove 7.

The plasma is not particularly limited, and nitrogen plasma, oxygen plasma, argon plasma, tetrafluoromethane plasma, or a plasma of a mixed gas thereof can be used.
The plasma treatment conditions are preferably such that the arithmetic mean roughness (Ra) of the first resin layer surface to the groove inner surface after the plasma step is 0.05 μm or more and 0.45 μm or less, At the same time, it is preferable that the conditions are such that carbides remaining on the inner surface of the groove 7 can be sufficiently removed. As a result, fine wiring with high insulation reliability and excellent signal response is possible. In a high frequency region exceeding 1 GHz, transmission loss due to the skin effect can be reduced, and further, plating defects in the grooves and interlayer connection failures can be reduced. Further, although not particularly limited, it is more preferable that the arithmetic average roughness (Ra) of the inner surface of the groove 7 of the resin layer after the plasma process is 0.05 μm or more and 0.30 μm or less. A condition of 0.1 μm or more and 0.25 μm or less is particularly preferable. Thereby, insulation reliability and signal responsiveness can be improved, transmission loss can be reduced, and further, an action that can reduce plating defects and interlayer connection defects in the groove 7 can be effectively expressed.

  Although the desmear by a chemical | medical solution is not specifically limited, Permanganate, dichromic acid, etc. can be used. Further, the desmear treatment conditions are such that the arithmetic average roughness (Ra) of the surface of the first resin layer 1 or the inner surface of the groove 7 after the desmear process is 0.05 μm or more and 0.45 μm or less. At the same time, it is preferable that the conditions are sufficient to completely remove the remaining carbide on the inner surface of the groove 7. As a result, it is possible to form vias with high insulation reliability, excellent signal responsiveness, and excellent reduction of plating defects and interlayer connection defects in the grooves. In a high frequency region exceeding 1 GHz, transmission loss due to the skin effect can be reduced. Further, although not particularly limited, it is more preferable that the arithmetic mean roughness (Ra) of the inner surface of the groove 7 after the desmearing process is 0.05 μm or more and 0.30 μm or less. It is particularly preferable that the conditions are 1 μm or more and 0.25 μm or less. Thereby, insulation reliability and signal responsiveness can be improved, transmission loss can be reduced, and the effect of reducing plating defects and interlayer connection defects in the grooves 7 can be effectively exhibited.

  If the desmear process by plasma or chemical solution is insufficient and carbides remain on the inner surface of the groove 7, the insulation reliability of the composite may be lowered. When the desmear process with plasma or chemical solution becomes excessive, the arithmetic average roughness (Ra) of the inner surface of the groove 7 of the insulating layer 6 in contact with the conductor layer 8 becomes rough, and the surface roughness of the conductor layer 8 causes the wiring signal due to the skin effect. There is a possibility that the responsiveness may be deteriorated, or the plating in the groove 7 or the interlayer connection may be defective.

In the step (D) of the present invention, the electroless plating layer 12 is formed on the surface of the first resin layer 1.
The type of metal of the electroless plating layer 12 is not particularly limited, but copper, nickel and the like are preferable. With these metals, the adhesion between the insulating layer 6 and the electroless plating layer 12 is good. The thickness of the electroless plating layer is not particularly limited, but is preferably about 0.1 μm or more and 5 μm or less. Furthermore, after the electroless plating, by performing heat treatment at 150 ° C. to 200 ° C. for 10 minutes to 120 minutes with a hot air drying device, the adhesion between the first resin layer 1 and the electroless plating layer 12 can be made better. it can.

In the manufacturing method of the printed wiring board of this invention, it is preferable to include the process of forming the electrolytic plating layer 13 further by electrolytic plating in a process (E). In this step, the inside of the groove 7 formed by the laser beam 10 can be filled with the electrolytic plating layer 13.
For the electrolytic plating, copper sulfate electrolytic plating can be used. Moreover, although not specifically limited, it is preferable that additives, such as a leveler agent, a polymer, and a brightener agent, are contained in a plating solution. As a result, plating is preferentially deposited on the inside of the groove 7 formed in the first resin layer 1 and is filled with the electrolytic plating layer 13, and the plating deposition level on the resin surface layer and the groove 7 after electrolytic plating is It becomes equivalent. The thickness of the electrolytic plating layer 13 is not particularly limited, but is preferably about 5 μm or more and 25 μm or less from the surface of the first resin layer 1.

In the step (F) of the present invention, a portion of the conductor 14 formed by the electroless plating layer 12 and the electrolytic plating layer 13 is removed, so that only the portion of the groove 7 has the electroless plating layer 12 ′ and the electrolytic plating. A conductor layer 8 composed of the layer 13 'is formed. Although not particularly limited, a method of removing a part of the conductor 14 formed by electrolytic plating is preferably a chemical etching process, a polishing process, a buffing process, or the like. Thereby, it is possible to effectively remove only the conductor 14 on the surface layer of the first resin layer 1 and leave the conductor layer 8 only in the groove 7 portion.
In this way, it is possible to produce a printed wiring board excellent in electrical reliability, signal responsiveness, plating property inside the groove, and interlayer connectivity.

The manufacturing method of this invention can include the process (G) of forming another insulating layer 15 on the insulating layer 6 and the conductor layer 8 after a process (F).
In the step (G) of the present invention, by forming another insulating layer 15 on the insulating layer 6 and the conductor layer 8, each conductor layer that becomes the wiring of the multilayer printed wiring board is covered with the insulating layer, so Insulation is ensured. Although not particularly limited, as a method of forming another insulating layer 15 on the insulating layer 6 and the conductor layer 8, as in the case of preparing the insulating layer 6, a resin sheet with a carrier film is, for example, a vacuum pressure type. Examples thereof include a method using a laminator device, a flat plate press device and the like.

  By repeating the steps (A) to (F), it is possible to produce a multilayer printed wiring board excellent in electrical reliability, signal responsiveness, plating property inside grooves and via holes, and interlayer connectivity.

On the other hand, when the first resin layer is mainly composed of a photosensitive resin as a curable resin, the first resin in steps (B) and (C) among the steps (A) to (G) shown in FIG. Layer patterning is performed by photolithography rather than laser processing.
Patterning by photolithography is performed by irradiating (exposure) active energy rays 10 'through a mask 11' with a circuit pattern, followed by development processing.
In the patterning by the photolithography method, when the photosensitive resin contained in the first resin layer is a negative type, the exposed portion is cured and the unexposed portion is selectively removed by a development process. When the photosensitive resin is a positive type, the exposed portion is decomposed and the exposed portion is selectively removed by development processing.

As the active energy ray 10 ′, laser light having a maximum wavelength in the range of 350 to 410 nm, light emission by discharge of mercury vapor using a short arc lamp, a (super) high pressure mercury lamp, or the like as a light source can be used. The type of the active energy ray 10 ′ may be either a gas laser or a solid laser.
Although the exposure amount of the active energy ray 10 ′ varies depending on the thickness of the resin layer and the like, it is generally 20 to 900 mJ / cm ² , particularly preferably 50 to 600 mJ / cm ² .
The exposure machine is not particularly limited, and for example, an ultraviolet irradiation device, a direct drawing device, or the like can be used.

  The development treatment can be performed by dipping method, shower method, spray method, brush method, etc. As the developer, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate Alkaline aqueous solutions such as ammonia, tetraammonium hydroxide (TMAH) and amines can be used. Patterning is performed by appropriately adjusting the development time depending on the target groove depth.

Next, a semiconductor device will be described.
The semiconductor device of the present invention is characterized in that a semiconductor element is mounted on the printed wiring board according to the present invention.
A semiconductor device according to the present invention includes mounting a semiconductor element having a solder bump on the printed wiring board according to the present invention, connecting the printed wiring board and the semiconductor element via the solder bump, and the printed wiring board. And a liquid sealing resin between the semiconductor element and the semiconductor element.

  The solder bump is preferably made of an alloy made of tin, lead, silver, copper, bismuth or the like. The method for connecting the semiconductor element and the printed wiring board is to align the connection electrode portion on the printed wiring board and the solder bump of the semiconductor element using a flip chip bonder, etc. In addition, the solder bumps are heated to the melting point or higher by using a heating device, and the printed wiring board and the solder bumps are connected by fusion bonding. In order to improve connection reliability, a metal layer having a relatively low melting point such as a solder paste may be formed in advance on the connection electrode portion on the printed wiring board. Prior to this joining step, the connection reliability can be improved by applying flux to the surface layer of the solder bump and / or the electrode portion for connection on the printed wiring board.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

  Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-2 are Examples and Comparative Examples using a negative first resin layer mainly composed of a photosensitive resin. Table 1 shows the content (parts by weight) of the components of the resin sheets obtained in Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-2.

(Example 1-1)
1. Preparation of first resin varnish 45 parts by weight of compound A as an alkali-soluble photosensitive resin, 25 parts by weight of naphthalene-modified cresol novolac epoxy resin (manufactured by DIC, HP-5000) as an epoxy resin, bis A type epoxy 10 parts by weight of resin (Mitsubishi Chemical Co., Ltd., jER828EL), 14 parts by weight of trimethylolpropane trimethacrylate (manufactured by Kyoeisha Chemical Co., Light Ester TMP) as a photopolymerizable compound, and biphenylaralkyl type phenolic resin (Maywa Kasei Co., Ltd.) as a curing agent Company, MEH7851-4L) 4 parts by weight, 2 parts by weight of 2,2dimethoxy-1,2-diphenylethane-1-one (manufactured by Nagase Sangyo Co., Ltd., Irgacure 651) as a photopolymerization initiator are mixed and dissolved in a methyl ethyl ketone solvent. To obtain a first resin varnish having a nonvolatile content of 65 parts by weight. It was.

(Synthesis Example 1)
The compound A (methacryloyl-modified novolak bisphenol A resin) was charged with 500 g of a novolak bisphenol resin (manufactured by DIC, Phenolite LF-6161, solid content 65 parts by weight) solution in a 2 L flask, and used as a catalyst. 1.65 g of tributylamine and 0.16 g of hydroquinone as a polymerization inhibitor were added and heated to 100 ° C. To this, 196 g of glycidyl methacrylate was added dropwise over 45 minutes, and the mixture was reacted with stirring at 100 ° C. for 5 hours to obtain a methacryloyl-modified novolak bisphenol A resin (methacryloyl modification rate 50%) having a solid content of 78%.

2. Preparation of second resin varnish 10 parts by weight of biphenyl dimethylene type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000), 20 parts by weight of phenol novolac type cyanate resin (manufactured by Lonza Japan, Primaset PT-30), curing agent 10 parts by weight of biphenyl aralkyl type phenol resin (Maywa Kasei Co., Ltd., MEH7851-4L) and 60 parts by weight of spherical silica D (manufactured by Admatechs, SO-25R, average particle size 0.5 μm) are mixed and dissolved in methyl ethyl ketone. The second resin varnish was obtained by adjusting the non-volatile content to 70 parts by weight.

3. Manufacture of carrier material The first resin varnish is applied to a PET film (polyethylene terephthalate, Purex film 36 μm made by Teijin DuPont Film) using a die coater so that the thickness of the first resin layer after drying is 15 μm. This was dried for 5 minutes with a dryer at 160 ° C. to obtain a resin sheet with PET for the first resin layer.
In addition, the second resin varnish was coated on a PET film (polyethylene terephthalate, Purex film 36 μm made by Teijin DuPont Film) in the same manner, and the thickness of the second resin layer after drying was 160 ° C. Was dried for 5 minutes to obtain a resin sheet with PET for the second resin layer.

4). Production of Resin Sheet A glass woven fabric (basis weight 12 g, thickness 13 μm, E glass weave manufactured by Unitika Glass Fiber Co., Ltd.) for the first resin layer-attached resin sheet with a PET film and for the second resin layer. The resin layer is placed on both sides of the cloth, IPC standard 1017) so that the resin layer is in contact with the glass woven cloth, and is heated and pressurized by a vacuum press at a pressure of 0.5 MPa and a temperature of 140 ° C. for 1 minute. Two resin materials were impregnated to obtain a resin sheet with a PET film on both sides. The first resin layer was 12 μm, the base material layer was 13 μm, the second resin layer was 15 μm, and the total thickness excluding the PET film was 40 μm.

5. Manufacturing of printed wiring boards and semiconductor devices Circuit pattern formation (residual copper ratio 70%, L / S = 50/50 μm, circuit) on core substrate (ELC-4785GS-B, manufactured by Sumitomo Bakelite Co., Ltd., thickness 0.2 mm, 9 μm copper foil) The PET film on the second resin layer side of the prepreg with the double-sided PET film obtained above is peeled off on the front and back of the inner layer circuit board having a height of 9 μm), and the both sides are laminated with the second resin layer inside. Then, using a vacuum pressurizing laminator device, vacuum heating and pressing were performed at a temperature of 130 ° C., a pressure of 0.2 MPa, and a time of 20 seconds, and laminated (evaluation substrate 1-1).

The PET film on the first resin layer side is peeled from the obtained laminate, and exposure (exposure) is performed using a lattice negative pattern mask with L / S = 8/8 μm and an exposure machine PLA-600FA (manufactured by Canon Inc.). Amount: 250 mJ / cm ² ). Subsequently, development was performed using 3% TMAH (developer pressure: 0.2 MPa, development time: 30 seconds) to form grooves having a target width of 8 μm, a target groove distance of 8 μm, and a target depth of 10 μm. After performing this both sides, it was heat-cured for 60 minutes at a temperature of 180 ° C. (evaluation substrate 1-2).

After the surface is subjected to degreasing, catalyst application, and activation steps, an electroless copper plating film is formed to have a thickness of about 0.2 μm, and the electroless copper plating layer is used as a power feeding layer. Pattern electrolytic copper plating (Okuno Pharmaceutical Co., Ltd., Top Lucina α) was performed at 3 A / dm ² for 30 minutes to form a conductor having a thickness of about 3 μm from the surface of the insulating layer. Next, after annealing at 200 ° C. for 60 minutes with a hot air dryer, the power feeding layer is removed by flash etching, the conductor layer height is aligned with the surface of the insulating layer, and fine wiring with L / S = 8/8 μm Processed.
This was repeated to obtain a multilayer wiring board having a 2-2-2 conductor layer (evaluation board 1-3).

  Next, a solder resist (manufactured by Taiyo Ink Manufacturing Co., Ltd., PSR-4000 AUS703) is printed, exposed with a predetermined mask so that the semiconductor element mounting pads and the like are exposed, developed and cured, and then on the circuit. The solder resist layer was formed to have a thickness of 12 μm.

  Finally, an electroless nickel plating layer of 3 μm is formed on the circuit layer exposed from the solder resist layer, and further, an electroless gold plating layer of 0.1 μm is formed thereon. A multilayer wiring board for a semiconductor device was obtained by cutting into a size of × 50 mm.

  The semiconductor device has a semiconductor element (TEG chip, size 15 mm × 15 mm, thickness 0.6 mm) having solder bumps mounted on the multilayer wiring board for the semiconductor device by means of thermocompression bonding using a flip chip bonder device, After melting and joining the solder bumps in an IR reflow furnace, a liquid sealing resin (manufactured by Sumitomo Bakelite Co., Ltd., CRP-4152S) was filled and the liquid sealing resin was cured. The liquid sealing resin was cured at a temperature of 150 ° C. for 120 minutes. In addition, the solder bump of the said semiconductor element used what was formed with the eutectic of Sn / Pb composition.

(Examples 1-2 to 1-10, Comparative Examples 1-1 to 1-2)
Except having implemented with the compounding quantity of Table 1, it carried out similarly to Example 1-1.
In addition, the compound B described in Table 1 is a methacryloyl-modified phenol novolac type resin, and was prepared according to Synthesis Example 2 below.

(Synthesis Example 2) Synthesis of methacryloyl-modified phenol novolac resin 500 g of a phenol novolak resin (manufactured by DIC, Phenolite TD-2090-60M, solid content 60% by weight) solution was put into a 2 L flask and used as a catalyst. 1.7 g of tributylamine and 0.17 of hydroquinone as a polymerization inhibitor were added and heated to 100 ° C. Into this, 205 g of glycidyl methacrylate was added dropwise over 45 minutes, and the mixture was reacted with stirring at 100 ° C. for 5 hours to obtain a methacryloyl-modified phenol novolak resin (methacryloyl modification rate 50%) having a solid content of 75%.

  Moreover, as a carboxyl group-containing (meth) acrylic acid ester shown in Table 1, Daicel Chemical Industries, Ltd. cyclomer PACA200M was used, and as a naphthalene dimethylene type epoxy resin, Toto Kasei Kogyo Co., Ltd., ESN-175 was used. YX-8800 manufactured by Mitsubishi Chemical Corporation is used as the anthracene type epoxy resin, PR-53647 manufactured by Sumitomo Bakelite Co. is used as the phenol novolak resin, and NSS-3N (average particle diameter manufactured by Tokuyama Co., Ltd. is used as the spherical silica A. 0.125 μm, coarse particle exceeding 2 μm 10 ppm), Admatech made by Admatech as spherical silica B (average particle diameter 55 nm, coarse particle less than 5 ppm less than 2 μm) and spherical silica C as Admatex Manufactured SO-32R (average particle diameter 1.1 μm, coarse particles exceeding 2 μm 3.3%), as a naphthalene aralkyl-type cyanate resin, a derivative of SN485 manufactured by Nippon Steel Chemical Co., Ltd. obtained by Synthesis Example 3 below, and as a boehmite, a BMB (average particle diameter) manufactured by Kawai Lime Industry Co., Ltd. Coarse grains (450 ppm exceeding 0.5 μm and 2 μm) were used.

(Synthesis Example 3) Synthesis of naphthalene aralkyl type cyanate resin Naphthalene aralkyl type phenol (SN485, Nippon Steel Chemical Co., Ltd., hydroxyl equivalent 215 g / eq) 101 g (0.47 mol hydroxyl group) and methyl isobutyl ketone (hereinafter MIBK) 400 g Charge and dissolve with stirring at room temperature. After dissolution, it was cooled to -10 ° C. At −10 ° C., 110 g of cyanogen bromide (hereinafter BrCN) was added (purity 95%, 0.987 mol), and when the internal temperature reached −15 ° C., 100 g (0.99 mol) of triethylamine (hereinafter TEA) and 600 g of MIBK The mixture was added dropwise over 1 hour. After the dropwise addition, the mixture was further aged for 30 minutes, and further aged for about 2 hours to complete the reaction. To the obtained solution, 400 ml of pure water was added for liquid separation, and further 1000 ml of 5% aqueous hydrogen chloride solution (HCl) was added for liquid separation. Furthermore, it was washed and separated twice with 500 g of 10% saline and washed twice with 500 ml of pure water.
The organic layer was dehydrated with anhydrous sodium sulfate, and then the solvent was removed under reduced pressure to obtain a solid resin. The obtained solid was washed with hexane and then dried under reduced pressure to obtain a naphthol aralkyl cyanate ester resin. The biphenylaralkyl cyanate thus obtained was analyzed by infrared absorption spectrum measurement (IR Prestige-21, KBr transmission method, manufactured by Shimadzu Corporation), and the absorption band of phenolic hydroxyl group was 3200 to 3600 cm ^−1. Disappeared, and the vicinity of 2264 cm ^−1, which is an absorption band of nitrile cyanate ester, was confirmed.

  Hereinafter, Examples 2-1 to 2-11 and Comparative Example 2-1 are examples and comparative examples using a first resin layer mainly composed of a thermosetting resin. Table 2 shows the content (parts by weight) of the components of the resin sheets obtained in Examples 2-1 to 2-11 and Comparative Example 2-1.

(Examples 2-1 to 2-11, Comparative Example 2-1)
Examples 2-1 to 2-10 and Comparative Example 2-1 were prepared in the same manner as in Example 1-1 except that the compounding amounts shown in Table 2 were used, and the first resin varnish was prepared. Preparation, production of carrier materials, and production of resin sheets were performed. In addition, YX-8100BH30 (solid content 30% by weight) manufactured by Mitsubishi Chemical Corporation is used as the bis S / biphenyl type phenoxy resin described in Table 2, and Curazole 2E4MZ or Shikoku Chemicals Co., Ltd. manufactured by Shikoku Kasei Kogyo Co., Ltd. is used as the curing accelerator. CURESOL 1B2PZ manufactured by Kogyo Co., Ltd. was used. Other components were the same as those described in Table 1 used in Examples 1-1 to 1-10 and Comparative Examples 1-1 and 1-2. In addition, SO-25R manufactured by Admatechs, which is used as spherical silica D, had an average particle diameter of 0.5 μm, and coarse particles exceeding 2 μm were 5000 ppm.
Example 2-11 is a glass woven fabric (basis weight 11 g, thickness) instead of E glass woven fabric (IPC standard 1017) manufactured by Unitika Glass Fiber Co., Ltd. as a base material used in the base material layer in the blending amounts shown in Table 2. 10 μm, E glass woven fabric manufactured by Asahi Kasei E-materials, IPC standard 1000), the first resin layer is 10 μm, the base material layer is 10 μm, the second resin layer is 20 μm, and the total thickness excluding the PET film is Except having set it as 40 micrometers, it carried out similarly to Example 1-1, and prepared the 1st resin varnish, the preparation of the 2nd resin varnish, manufacture of carrier material, and manufacture of the resin sheet.
In Examples 2-1 to 2-11 and Comparative Example 2-1, the method of manufacturing the printed wiring board and the semiconductor device is the same as that of Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-2. The following method was used.

5. Production of printed wiring board and semiconductor device A circuit pattern was formed on a core substrate (ELC-4785GS-B, thickness 0.2 mm, 9 μm copper foil manufactured by Sumitomo Bakelite Co., Ltd.) (residual copper ratio 70%, L / S = 50/50 μm). The PET on the second resin layer side of the prepreg with the double-sided PET film obtained above is peeled off on the front and back of the inner layer circuit board, and the both sides are overlapped with the second resin layer inside, and this is a vacuum-pressurizing laminator device Was subjected to vacuum heating and pressure molding at a temperature of 130 ° C., a pressure of 0.2 MPa, and a time of 20 seconds, and then heat-cured at 170 ° C. for 60 minutes with a hot air dryer (evaluation substrate 2-1).

  The PET film was peeled from the obtained laminate, and a target width of 8 μm, a target groove distance of 8 μm, a target depth by an excimer laser having a wavelength of 193 nm using a lattice pattern mask of L / S = 8/8 μm. A groove having a thickness of 10 μm was formed, and the obtained laminate was immersed in a swelling solution at 60 ° C. (Swelling Dip Securigant P500, manufactured by Atotech Japan Co., Ltd.) for 10 minutes, and further an aqueous potassium permanganate solution at 80 ° C. ( After being immersed in Atotech Japan Co., Ltd., Concentrate Compact CP) for 20 minutes, it was neutralized and subjected to desmear treatment (evaluation substrate 2-2).

After the surface is subjected to degreasing, catalyst application, and activation steps, an electroless copper plating film is formed to have a thickness of about 0.2 μm, and the electroless copper plating layer is used as a power feeding layer. Pattern electrolytic copper plating (Okuno Pharmaceutical Co., Ltd., Top Lucina α) was performed at 3 A / dm ² for 30 minutes to form a conductor having a thickness of about 3 μm from the surface of the insulating layer. Next, after performing an annealing process at 200 ° C. for 60 minutes with a hot air dryer, the power feeding layer is removed by flash etching (SAC process manufactured by Ebara Densan Co., Ltd.), and the conductor layer height is aligned with the surface of the insulating layer. Fine wiring processing of L / S = 8/8 μm was performed.
This was repeated to obtain a multilayer wiring board having a 2-2-2 conductor layer (evaluation board 2-3).

  Next, a solder resist (manufactured by Taiyo Ink Mfg. Co., Ltd., PSR-4000 AUS703) is printed, exposed with a predetermined mask so that the semiconductor element mounting pads and the like are exposed, developed, cured, and a solder resist layer It formed so that thickness might be set to 12 micrometers.

  Finally, an electroless nickel plating layer of 3 μm is formed on the circuit layer exposed from the solder resist layer, and further, an electroless gold plating layer of 0.1 μm is formed thereon. A multilayer wiring board for a semiconductor device was obtained by cutting into a size of × 50 mm.

  The semiconductor device has a semiconductor element (TEG chip, size 15 mm × 15 mm, thickness 0.6 mm) having solder bumps mounted on the multilayer wiring board for the semiconductor device by means of thermocompression bonding using a flip chip bonder device, After melting and joining the solder bumps in an IR reflow furnace, a liquid sealing resin (manufactured by Sumitomo Bakelite Co., Ltd., CRP-4152S) was filled and the liquid sealing resin was cured. The liquid sealing resin was cured at a temperature of 150 ° C. for 120 minutes. In addition, the solder bump of the said semiconductor element used what was formed with the eutectic of Sn / Pb composition.

(Evaluation)
The following evaluation was performed about the resin sheet, printed wiring board, and semiconductor device which were obtained by the Example and the comparative example. The evaluation items are shown together with the contents. The evaluation results obtained in Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-2 are shown in Table 1, and obtained in Examples 2-1 to 2-11 and Comparative Example 2-1. The evaluation results are shown in Table 2. The items that could not be evaluated due to the inability to process the grooves were described as “unprocessable” in the table.

(1) Thermal expansion coefficient (50-100 ° C)
The thermal expansion coefficient is 4 mm × 20 mm using a TMA (thermomechanical analysis) apparatus (TA Instruments, Q400), temperature range 30 to 300 ° C., 10 ° C./min, load The linear expansion coefficient (CTE) at 50 to 100 ° C. in the second cycle was measured under the condition of 5 g. In addition, as an evaluation sample, two resin sheets obtained in each Example and Comparative Example were used, the second resin layer was faced, and press lamination was performed under conditions of a temperature of 220 ° C., a pressure of 1 MPa, and a time of 120 minutes. A thing was used.

(2) Embeddability After the entire surface of the outer layer copper foils of the evaluation substrate 1-1 and the evaluation substrate 2-1 were etched, the embedding property into the inner layer pattern was visually observed, and further, cross-sectional observation was performed and evaluated.
The symbols are as follows.
◎: There is no problem of embedment on the whole surface. ○: There is virtually no problem.
×: Pattern embedding failure

(3) Fine wire workability (L / S = 8/8 μm)
(Examples 1-1 to 1-10, Comparative Examples 1-1 to 1-2)
The groove pattern part of the evaluation board | substrate 1-2 was observed with the electron microscope (x2,000 times), and the presence or absence of a residue and a shape was evaluated. Moreover, the shape of the conductor layer was confirmed from the cross section of the evaluation substrate 1-3. The pattern mask used was a grid having a groove width of 8 μm and a groove interval of 8 μm.
Each code is as follows.
(Double-circle): A residue is not confirmed at all, and a shape is a substantially trapezoid, and there is no problem practically.
○: Some residue can be confirmed, but the shape is substantially trapezoidal and is at a level that is not problematic in practice.
Δ: A relatively large amount of residue is observed, which is not at a practical level.
X: Many residues are confirmed and it is not a practical use level.
(Examples 2-1 to 2-11, Comparative Example 2-1)
The groove pattern part of the evaluation board | substrate 2-2 was observed with the electron microscope (x2,000 times), and the presence or absence of the residue was evaluated. In addition, the shape of the conductor layer was confirmed from the cross section of the evaluation substrate 2-3, and a pattern mask having a groove width of 8 μm and a groove interval of 8 μm was used.
Each code is as follows.
(Double-circle): A residue is not confirmed at all, and a shape is a substantially trapezoid, and there is no problem practically.
○: Some residue can be confirmed, but the shape is substantially trapezoidal and is at a level that is not problematic in practice.
Δ: A relatively large amount of residue is observed, which is not at a practical level.
X: Many residues are confirmed and it is not a practical use level.

(4) Arithmetic average roughness (Ra) and 10-point average roughness (Rz) of the conductor layer wall surface
From the cross-section of the conductor wiring, arithmetic average roughness (Ra) and 10-point average roughness (Rz) were calculated according to JIS B0601. In addition, the evaluation board | substrate 1-2 and the evaluation board | substrate 2-2 were used for the evaluation sample.

(5) Insulation reliability between lines (HAST)
A line insulation reliability test was performed under the conditions of an applied voltage of 3.3 VDC, a temperature of 130 ° C., and a humidity of 85%. In addition, the evaluation board | substrate 1-3 of 2-2-2 board | substrate and the evaluation board | substrate 2-3 were used for the evaluation sample.
When the insulation resistance value was less than 1 × 10 8 Ω, it was judged as defective and the test was terminated.
Each code is as follows.
◎: Good 500 hours or more ○: Virtually no problem 200 hours or more and less than 500 hours ×: Unusable Less than 200 hours

(6) Evaluation of Semiconductor Device The semiconductor device obtained above was pretreated at a temperature of 30 ° C., a humidity of 60% and a time of 192 hours in accordance with IPC / JEDEC J-STD-20. The temperature was passed through a reflow furnace reaching 3 ° C. three times, and 500 cycles of −50 ° C. for 30 minutes and 125 ° C. for 30 minutes were performed as post-treatment. The evaluation was carried out by conducting resistance evaluation and cross-sectional observation of the semiconductor element after the pretreatment and after the temperature cycle of 500 cycles.
Each code is as follows.
A: No conduction resistance abnormality after 500 cycles of treatment and no abnormality of conductor circuit and via in cross-sectional observation. ○: Conduction resistance after 500 cycles of treatment rises in the range of less than 1 to 10%, but cross section. No abnormality in conductor circuit and via in observation ×: The conduction resistance after 500 cycles of post-treatment is increased by 10%. Or micro voids or peeling cracks occur between the conductor circuit and the resin or between the via and the resin.

(7) Flame retardancy (reference example)
According to the UL-94 standard, it was measured by the vertical method. In addition, after placing 12 μm copper foil on both surfaces of the core substrate which has been entirely etched through a resin sheet, press molding at a temperature of 200 ° C. for 1 hour and a pressure of 2 MPa, and then etching the copper foil to a thickness of 0.28 mm as a test piece did. The evaluation of flame retardancy was performed only on the samples obtained in Examples 2-1, 2-2 and 2-8.

(Evaluation results)
Since Comparative Example 1-1 did not include a photosensitive resin as the curable resin included in the first resin layer, the groove processing by the photolithography method could not be performed.
In Comparative Examples 1-2 and 2-1, since the coarse particles exceeding 2 μm in the inorganic filler contained in the first resin layer are too large as 3.3%, the arithmetic average roughness (Ra ) Is too large, the thin wire workability is poor, and the 10-point average roughness (Rz) of the conductor layer wall surface is too large, resulting in poor line insulation reliability. Furthermore, in the obtained semiconductor device, the conduction resistance of the semiconductor element after 500 cycles of the temperature cycle is increased by 10%, and in the cross-sectional observation, there is a microvoid between the conductor circuit and the resin or between the via and the resin. The peeling crack was generated.
Meanwhile, in Examples 1-1 to 1-10 and Examples 2-1 to 2-10, the first resin layer includes at least a curable resin, and the second resin layer includes a thermosetting resin and an inorganic filling. Including the material and the thickness is 5 to 30 μm, the unevenness of the wall surface of the conductor layer formed in the first resin layer is appropriate, excellent in fine wire workability and interline insulation reliability, and circuit embedding in the second resin layer The semiconductor device had excellent conductivity and low thermal expansion, and the semiconductor device had no abnormality in conduction resistance of the semiconductor element after 500 cycles of temperature cycles, and there was no abnormality in the conductor circuit and via in the cross-sectional observation.
Moreover, as a reference example, when flame retardancy was evaluated with the samples obtained in Examples 2-1, 2-2 and 2-8, Example 2-1 was excellent in flame retardancy. In Examples 2-2 and 2-8, the flame retardancy was inferior to that of Example 2-1. This is because Example 2-2 was not a naphthalene-modified cresol novolac epoxy resin but an bis-A type epoxy resin as an epoxy resin, and Example 2-8 did not use a cyanate resin. to cause.

DESCRIPTION OF SYMBOLS 1 1st resin layer 2 2nd resin layer 1a 1st carrier material 2a 2nd carrier material 3 Carrier film 4 Carrier film 5 Base material layer 5a Base material 6 Insulating layer 7 Groove 8 Conductor layer 9 Inner layer circuit board 9a Conductor circuit 9b Glass Epoxy substrate 10 Laser beam 11 Mask 12 Electroless plating layer 12 ′ Electroless plating layer 13 Electrolytic plating layer 13 ′ Electrolytic plating layer 14 Conductor 15 Another insulating layer 100 Resin sheet 100 ′ Resin sheet 101 Build-up layer 200 Printed wiring board

Claims (25)

It is a resin sheet having a multilayer structure including a first resin layer that forms one surface side and a second resin layer that forms the other surface side,
The first resin layer includes at least a curable resin,
Said 2nd resin layer contains a thermosetting resin and an inorganic filler, and thickness is 5-30 micrometers, The resin sheet characterized by the above-mentioned.   The surface of at least said 1st resin layer is coat | covered with the carrier film chosen from the group which consists of a polymer film and copper foil whose 10-point average roughness (Rz) of a surface is 4.0 micrometers or less. Resin sheet.   The resin sheet according to claim 1 or 2, wherein the first resin layer further contains an inorganic filler, and the coarse particles exceeding 2 µm in the inorganic filler are 500 ppm or less.   The resin sheet according to claim 3, wherein the content of the inorganic filler contained in the first resin layer is 1 to 60% by weight.   The resin sheet of Claim 3 or 4 whose average particle diameter of the inorganic filler contained in said 1st resin layer is 0.01-0.4 micrometer.   The resin sheet according to claim 3, wherein the inorganic filler is spherical silica.   The resin sheet according to claim 1, wherein the first resin layer does not include an inorganic filler.   The resin sheet according to any one of claims 1 to 7, wherein the curable resin contained in the first resin layer includes a thermosetting resin and / or a photosensitive resin.   The resin sheet according to claim 8, wherein the thermosetting resin includes at least one selected from an epoxy resin, a phenol resin, a cyanate resin, and a benzocyclobutene resin.   The second resin layer includes an epoxy resin, an amorphous first inorganic filler, a second inorganic filler having an average particle diameter different from that of the first inorganic filler, and an average particle diameter of 10 to 100 nm. The resin sheet as described in any one of Claims 1 thru | or 9 containing these.   The second resin layer includes an epoxy resin, silicone rubber fine particles having an average particle size of 1 μm to 10 μm, boehmite fine particles having an average particle size of 0.2 μm to 5 μm, and silica nanoparticles having an average particle size of 10 nm to 100 nm. Item 11. The resin sheet according to any one of Items 1 to 10.   The resin sheet as described in any one of Claims 1 thru | or 11 containing a base material layer between said 1st resin layer and said 2nd resin layer.   The resin sheet according to claim 12, which has a three-layer structure including the first resin layer, the base material layer, and the second resin layer.   The resin sheet according to claim 12 or 13, wherein the substrate used for the substrate layer is a glass cloth.   The resin sheet as described in any one of Claims 1 thru | or 14 whose thickness of said 1st resin layer is 6-28 micrometers.   The resin sheet according to claim 15, wherein the thickness of the first resin layer is 15 to 50% of a total thickness of the thickness of the first resin layer and the thickness of the second resin layer.   The resin sheet as described in any one of Claims 1 thru | or 16 whose whole thickness is 60 micrometers or less.   The resin sheet according to any one of claims 1 to 16, or the resin sheet is laminated at the position of the outermost layer on at least one side so that the first resin layer faces the surface side. Laminated board.   The insulating layer which consists of the hardened | cured material of the resin sheet as described in any one of the said Claims 1 thru | or 17, the groove | channel provided in the surface of the 1st resin layer of the said insulating layer, and the conductor provided in the said groove | channel An electronic component comprising a conductor track structure having a layer.   The insulating layer which consists of the hardened | cured material of the resin sheet as described in any one of the said Claims 1 thru | or 17, the groove | channel provided in the surface of the 1st resin layer of the said insulating layer, and the conductor provided in the said groove | channel A printed wiring board comprising at least one buildup layer having a layer.   The printed wiring board according to claim 20, wherein the maximum width of the groove is 1 to 10 μm.   The printed wiring board of Claim 20 or 21 whose arithmetic mean roughness (Ra) of the surface of the said groove | channel which contact | connects the said conductor layer is 0.05-0.45 micrometer. The depth of the groove is 2 to 20 μm;
The printed wiring board according to any one of claims 20 to 22, wherein a thickness of the first resin layer is 1.2 to 1.4 times a depth of the groove. The height of the conductor circuit covered with the build-up layer is 5 to 20 μm,
The printed wiring board according to any one of claims 20 to 23, wherein a thickness of the second resin layer is 1 to 1.5 times a height of the conductor circuit.   25. A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to any one of claims 20 to 24.

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