TW202028009A - Manufacturing method of multilayer circuit board for suppressing occurrence of damages to circuit layer while welding leads - Google Patents

Abstract

The subject of the present invention is to provide a method for suppressing occurrence of damages to the circuit layer while welding leads. The present invention provides a manufacturing method of multilayer circuit board, which includes: (1) a resin layer preparation step for preparing a resin sheet having a peeling layer and a resin composition layer disposed on one surface of the peeling layer; (2) a circuit board preparation step for preparing a circuit board having a substrate and a circuit layer formed on a part of the surface of the substrate; (3) a step for laminating the resin sheet on the circuit board which penetrates from the circuit layer through the resin composition layer to reach the peeling layer; and (4) a step for removing the peeling layer to expose a part of the circuit layer.

Description

Manufacturing method of multilayer circuit board

The present invention relates to a manufacturing method of a laminated circuit board and a resin sheet used in the manufacturing method.

As a manufacturing method of a circuit board, a build-up method of alternately stacking a circuit layer and an insulating layer is widely used, and the circuit layer is used as a conductor layer with lines formed. Furthermore, it is known that the insulating layer is formed of a hardening material that hardens a resin composition. In recent years, the lighter, thinner, shorter and smaller electronic devices have progressed, and in order to make the circuit board thinner, a circuit board having an embedded circuit layer is required (for example, refer to Patent Document 1). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2017-82201 A

[The problem to be solved by the invention]

In the past, when manufacturing a circuit board with an embedded circuit layer, in order to expose the embedded circuit layer buried in the insulating layer, the insulating layer had to be polished. However, the polishing system requires special equipment and some It is a technical problem that it is difficult to grind the circuit layer and the insulating layer flatly. In particular, it is difficult to grind materials with different characteristics, such as circuit layers, inorganic fillers, and resin components, on the same surface, and the yield becomes low. Therefore, in order to avoid grinding as much as possible and to efficiently manufacture a printed circuit board, there are cases where a circuit board with a circuit layer formed on an inner layer circuit board in advance is used. However, in such a circuit board, when the conductive wire is soldered on the circuit layer or when the parts after soldering are installed, the circuit layer may fall, and the circuit layer may be damaged. The subject of the present invention is to provide a method for suppressing the damage of the circuit layer that occurs when such a conductive wire is soldered. [Means to solve the problem]

In order to achieve the subject of the invention, the inventors intensively reviewed and found that by providing a side support circuit layer with a resin composition layer (hardened body layer), the occurrence of damage to the circuit layer can be suppressed, and finally completed this invention.

That is, the present invention includes the following contents. [1] A manufacturing method of a multilayer circuit board, which includes: (1) A step of preparing a resin sheet having a release layer and a resin composition layer provided on one surface of the release layer, (2) The step of preparing a circuit board having a substrate and a circuit layer formed on a part of the surface of the substrate, (3) The step of laminating the resin sheet on the circuit board so that the circuit layer penetrates the resin composition layer and reaches the release layer, and (4) The step of removing the peeling layer to expose a part of the circuit layer. [2] The method for manufacturing a multilayer circuit board as described in [1], wherein the resin composition layer contains a thermosetting resin. [3] The method for manufacturing a multilayer circuit board as described in [2], wherein the resin composition layer includes (A) epoxy resin and (B) curing agent. [4] The method for manufacturing a multilayer circuit board as described in any one of [1] to [3], wherein the release layer comprises a cellulose resin, a polyvinyl acetal resin, a poly(meth)acrylate resin, One or more resins in the group consisting of polyester resin, polybutadiene resin, polyimide resin and epoxy resin. [5] The method for manufacturing a multilayer circuit board according to any one of [1] to [4], wherein the minimum melt viscosity of the release layer is higher than the minimum melt viscosity of the resin composition layer. [6] The method for manufacturing a multilayer circuit board as described in any one of [1] to [5], wherein the minimum melt viscosity of the peeling layer is 10,000 poise or more. [7] The method for manufacturing a multilayer circuit board as described in any one of [1] to [6], wherein the minimum melt viscosity of the resin composition layer is 5,000 poise or less. [8] The method for manufacturing a multilayer circuit board as described in any one of [1] to [7], wherein after step (3) and before step (4), or after step (4), further comprising (5) ) The step of hardening the above-mentioned resin composition layer into a hardened body layer. [9] The method for manufacturing a multilayer circuit board as described in any one of [1] to [8], wherein the method for removing the peeling layer in step (4) is peeling removal. [10] The method for manufacturing a multilayer circuit board as described in [9], wherein the peeling strength of the peeling layer when the peeling layer is removed in step (4) is 200 gf/cm or less. [11] The method for manufacturing a build-up circuit board as described in any one of [1] to [8], wherein the removal method of the peeling layer in step (4) is dissolution removal. [12] The method for manufacturing a laminated circuit board as described in [11], wherein the thickness of the peeling layer before the lamination is 25 μm or less. [13] The method for manufacturing a laminated circuit board according to any one of [1] to [12], wherein the resin sheet further has a support provided on the surface of the release layer opposite to the resin composition layer body, After step (3) and before step (4), it further includes (6) the step of removing the support body, or in step (4), the support body is removed together with the peeling layer to make a part of the circuit layer Exposed. [14] The method for manufacturing a laminated circuit board according to any one of [1] to [13], wherein the thickness of the release layer before lamination is smaller than the thickness of the resin composition layer before lamination. [15] The method for manufacturing a laminated circuit board according to any one of [1] to [14], wherein the thickness of the peeling layer before lamination is A (μm), and the resin composition layer before lamination The thickness is regarded as B (μm), the height of the above-mentioned circuit layer is regarded as C (μm), and the ratio of the area of the above-mentioned circuit layer to the surface of the above-mentioned substrate in the range where the above-mentioned resin sheet is laminated in step (3) is regarded as When D(%) is used, the relationship becomes (A+B)/{C×(1-0.01×D)}>1. [16] A resin sheet, which is a resin sheet having a release layer and a resin composition layer provided on one surface of the release layer, and is used in a manufacturing method of a multilayer circuit board including the following steps: (1) The step of preparing the resin sheet, (2) the step of preparing a circuit board having a substrate and a circuit layer formed on a part of the surface of the substrate, and (3) the circuit layer penetrates the resin composition layer to reach The method of the peeling layer includes the step of laminating the resin sheet on the circuit board, and (4) the step of removing the peeling layer to expose a part of the circuit layer. [17] A resin sheet comprising a release layer and a resin composition layer provided on one surface of the release layer, The above-mentioned release layer comprises a group selected from the group consisting of cellulose resin, polyvinyl acetal resin, poly(meth)acrylate resin, polyester resin, polybutadiene resin, polyimide resin and epoxy resin One or more resins, the resin composition layer includes (A) an epoxy resin and (B) a hardener, and the minimum melt viscosity of the release layer is higher than the minimum melt viscosity of the resin composition layer. [Effects of the invention]

The multilayer circuit board obtained by the manufacturing method of the multilayer circuit board of the present invention can suppress the breakage of the circuit layer that occurs during soldering of conductive wires.

[The form of implementing the invention]

Hereinafter, the present invention will be described in detail with suitable embodiments. However, the present invention is not limited to the following embodiments and exemplified materials, and can be arbitrarily changed and implemented without departing from the scope of the present invention and its equivalent scope.

The manufacturing method of the multilayer circuit board of the present invention includes: (1) A step of preparing a resin sheet having a release layer and a resin composition layer provided on one surface of the release layer, (2) The step of preparing a circuit board having a substrate and a circuit layer formed on a part of the surface of the substrate, (3) The step of laminating the resin sheet on the circuit board in such a way that the circuit layer penetrates the above resin composition layer to reach the release layer, and (4) The step of removing the peeling layer to expose a part of the circuit layer.

FIG. 1 schematically shows a cross-sectional view of a circuit board 10 in an embodiment. As shown in FIG. 1, the circuit board 10 includes a substrate 12 and a circuit layer 11 having an arbitrary circuit pattern on a part of the surface. Conventionally, when a conductive wire is soldered to the circuit layer 11 of the circuit board 10 or when parts after soldering are installed, the circuit layer 11 may fall over, and the circuit layer 11 may be damaged. In contrast, according to the method of the present invention, since the resin composition layer (hardened body layer) supporting the circuit layer 11 on the side is provided, the occurrence of damage to the circuit layer 11 in the circuit board 10 can be suppressed.

<Step (1)> Step (1) is a step of preparing a resin sheet having a release layer and a resin composition layer.

In a suitable embodiment, the resin sheet further has a support. FIG. 2 is a cross-sectional view schematically showing the resin sheet 20 in this embodiment. In this embodiment, as shown in FIG. 2, the resin sheet 20 has a release layer 22, a resin composition layer 23 provided on one side of the release layer 22, and a resin composition layer 23 provided on the side of the release layer 22 opposite to the resin composition layer 23.面的Support 21.

The support 21 is an arbitrary layer that fixes the peeling layer 22 and the resin composition layer 23, and can be an arbitrary layer that can be a pressurized object during the lamination in the step (3) described below. Therefore, the support body 21 uses a material harder than the release layer 22 and the resin composition layer 23. As the support body 21, for example, a film made of a plastic material, a metal foil, a release paper, etc., is preferably a film made of a plastic material, or a metal foil.

When a film made of a plastic material is used as the support 21, the plastic material may, for example, be polyethylene terephthalate (hereinafter also referred to as "PET"), polyethylene naphthalate (hereinafter also referred to as Polyester such as "PEN"), polycarbonate (hereinafter also referred to as "PC"), polymethyl methacrylate (PMMA), acrylic, cyclic polyolefin, triacetyl cellulose ( TAC), polyether sulfide (PES), polyetherketone, polyimide, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

When a metal foil is used as the support 21, the metal foil includes, for example, copper foil, aluminum foil, etc., and copper foil is preferred. As the copper foil, a foil made of a single metal of copper can be used, and a foil made of an alloy of copper and other metals (such as tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) can also be used.

The support body 21 is attached to the peeling layer 22 and can be subjected to matting treatment, corona treatment, and antistatic treatment.

In addition, as the support 21, a support with a mold release layer having a mold release layer on the surface to be bonded to the release layer 22 can be used. As the mold release agent used in the mold release layer of the support with the mold release layer, for example, one selected from the group consisting of alkyd resin, polyolefin resin, urethane resin and polysiloxane resin More than one release agent. For the support system with a release layer, commercially available products can be used.

The thickness of the support 21 is not particularly limited, but it is preferably 5 μm or more, more preferably 10 μm or more, particularly preferably 15 μm or more, and particularly preferably 20 μm or more. The upper limit of the thickness is not particularly limited, but is preferably 100 μm or less, more preferably 70 μm or less, particularly preferably 50 μm or less, and particularly preferably 40 μm or less. In addition, when a support with a release layer is used, the thickness of the entire support with a release layer is preferably within the above-mentioned range.

The peeling layer 22 is a layer to which the circuit layer 11 reaches during the lamination of step (3) described below. The resin of the resin composition layer 23 flows during lamination and can have a fixing function. Furthermore, the peeling layer 22 is removed by the step (4) described below, so that a part of the circuit layer 11 is exposed.

In one embodiment, the release layer 22 is preferably made of cellulose resin, polyvinyl acetal resin, poly(meth)acrylate resin, polyester resin, polybutadiene resin, and polyimide resin. It is composed of one or more resin resin materials in the group of epoxy resin.

Examples of the cellulose resin include cellulose ether and cellulose ether ester.

As specific examples of cellulose ethers, for example, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxybutyl methyl cellulose, hydroxy ethyl Ethyl cellulose, carboxymethyl cellulose, etc.

Examples of cellulose ether esters include hydroxypropyl methyl cellulose esters, hydroxypropyl cellulose esters, and the like. Specific examples include hydroxypropyl methyl cellulose acetate and hydroxypropyl methyl cellulose acetate. -Based cellulose succinate, hydroxypropyl methylcellulose acetate succinate, hydroxypropyl methylcellulose phthalate, hydroxypropyl methylcellulose trimellitate, hydroxypropyl Methyl cellulose acetate phthalate, hydroxypropyl methyl cellulose acetate trimellitate, hydroxypropyl cellulose acetate phthalate, hydroxypropyl fiber Butyrate phthalate, hydroxypropyl cellulose acetate phthalate succinate and hydroxypropyl cellulose acetate trimellit succinate, etc.

As the cellulose resin, commercially available products can be used. Examples of commercially available products include "HP-55", "HP-50" (all hydroxypropyl methylcellulose phthalate), and "60SH-06" manufactured by Shin-Etsu Chemical Co., Ltd. Hydroxypropyl methylcellulose) and so on.

Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins. Specific examples of polyvinyl acetal resins include "Denka butyral 4000-2", "Denka butyral 5000-A", "Denka butyral 6000-C", and "Denka butyral 6000-EP" manufactured by Denka Chemical Industry Co., Ltd. "S-LEC BH series, BX series (such as BX-5Z), KS series (such as KS-1), BL series, BM series, etc. manufactured by Sekisui Chemical Industry Co., Ltd.

The poly(meth)acrylate resin is a resin having a poly(meth)acrylate structure in the molecule, for example, poly(meth)acrylate resin containing hydroxyl group, poly(meth)acrylate resin containing phenolic hydroxyl group Acrylate resin, poly(meth)acrylate resin containing carboxyl group, poly(meth)acrylate resin containing acid anhydride group, poly(meth)acrylate resin containing epoxy group, poly(meth)acrylate resin containing isocyanate group (Base) acrylate resin, poly(meth)acrylate resin containing urethane group, etc. In addition, the poly(meth)acrylate resin in this specification means polyacrylate resin and/or polymethacrylate resin.

Specific examples of poly(meth)acrylate resins include TEISANRESIN "SG-70L", "SG-708-6", "WS-023", "SG-700AS", and "SG" manufactured by Nagase ChemteX. -280TEA" (acrylate copolymer resin containing carboxyl group), "SG-80H", "SG-80H-3", "SG-P3" (acrylate copolymer resin containing epoxy group), "SG-600TEA ", "SG-790" (hydroxyl-containing acrylate copolymer resin), "ME-2000" manufactured by Negami Kogyo Co., Ltd., "W-116.3" (carboxyl group-containing acrylate copolymer resin), "W-197C" (Acrylate copolymer resin containing hydroxyl), "KG-25", "KG-3000" (Acrylic copolymer resin containing epoxy), etc.

Specific examples of polyester resins include "Plascoat Z-687", "Z-690", "Z-221", "Z-446", "Z-561" and " Z-450", "Z-565", "Z-850", "Z-3308", "RZ-105", "RZ-570", "Z-730", "RZ-142", Takamatsu Oil Co., Ltd. "Pesresin A-110", "A-124GP", "A-520", "A-640", "A-680", "Hydran HW350" manufactured by DIC, etc.

Specific examples of polybutadiene resins include "Ricon 130MA8", "Ricon 130MA13", "Ricon 130MA20", "Ricon 131MA5", "Ricon 131MA10", "Ricon 131MA17", and "Ricon 131MA20", "Ricon 184MA6" (polybutadiene containing acid anhydride groups), "GQ-1000" (polybutadiene with hydroxyl and carboxyl groups introduced) manufactured by Soda Corporation, "G-1000", "G-2000 ”, “G-3000” (Polybutadiene with two-terminal hydroxyl), “GI-1000”, “GI-2000”, “GI-3000” (Hydrogenated polybutadiene with two-terminal hydroxyl), manufactured by Nagase ChemteX "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin), etc.

As a specific example of the polyimide resin, "Rikacoat SN20" and "Rikacoat PN20" manufactured by Nippon Rika Co., Ltd. can be cited.

As an epoxy resin, the same thing as (A) component which can be contained in the resin composition layer demonstrated below is mentioned.

The above-mentioned resin system can be used individually by 1 type or in combination of 2 or more types.

As the release layer 22 made of polyimide resin, a commercially available polyimide resin film can be used. As a specific example of a commercially available polyimide resin film, "PFE type", "PFG type", "PFH type", "PFK type", etc. of Protect films manufactured by Arisawa Manufacturing Co., Ltd. can be cited.

The minimum melt viscosity of the peeling layer 22 is preferably 3,000 poise or more, more preferably 5,000 poise or more, particularly preferably 10,000 poise or more, particularly preferably 20,000 poise or more from the viewpoint of remarkably obtaining the desired effect of the present invention.

The minimum melt viscosity of the release layer 22 may be the same as the minimum melt viscosity of the resin composition layer 23, or may be higher or lower than the minimum melt viscosity of the resin composition layer 23, but the resin composition layer 23 is sufficiently From the viewpoint of flow, it is preferably higher than the minimum melt viscosity of the resin composition layer 23. In addition, the elastic modulus of the release layer 22 is preferably higher than the elastic modulus of the resin composition layer 23 from the viewpoint of allowing the resin of the resin composition layer 23 to flow sufficiently.

The thickness of the release layer 22 before lamination is not particularly limited as long as it is within a range that can exhibit the desired effect of the present invention, but is preferably 0.1 μm or more, more preferably 1 μm or more, and particularly preferably 2 μm or more. Especially preferably, it is 3 μm or more. The upper limit of the thickness is not particularly limited as long as it is within the range where the desired effect of the present invention can be exhibited, but it is preferably 25 μm or less, more preferably 20 μm or less, particularly preferably 15 μm or less, and particularly preferably 10 μm or less.

The resin composition layer 23 is a layer through which the circuit layer 11 penetrates at the time of lamination in the step (3) described below. As long as the material of the resin composition layer 23 is used for lamination, for example, by laminating with a laminating device or the like, and if necessary, pressing with a flat pressing device or the like, there is no particular matter that can penetrate the circuit layer 11 However, since the resin composition layer 23 can eventually become a part of the surface layer of the circuit board, it is preferable to further have the property of being easily hardened. The resin composition layer 23 contains, for example, a thermosetting resin and/or a photocurable resin, and preferably contains a thermosetting resin.

Examples of thermosetting resins include epoxy resins, oxetane resins, phenol resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, thermosetting polyimide resins, and thermosetting resins. The urethane resin, hydrosilylation cross-linked resin, etc. are preferably epoxy resin. Therefore, the resin composition layer 23 preferably contains a combination of (A) epoxy resin and (B) hardener.

Examples of (A) epoxy resins include bixylenol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and bisphenol AF type epoxy resins. Oxygen resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol novolak type epoxy resin, phenol novolak type epoxy resin, tertiary butylcatechol type epoxy resin, naphthalene Type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type Epoxy resin, linear aliphatic epoxy resin, epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexane epoxy resin Resin, cyclohexane cyclohexane type epoxy resin, naphthyl ether type epoxy resin, trimethylol type epoxy resin, tetraphenyl ethane type epoxy resin, etc. The epoxy resin may be used alone or in combination of two or more types.

The resin composition layer 23 preferably contains an epoxy resin having two or more epoxy groups in one molecule as the (A) epoxy resin. The ratio of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, and more preferably 60% by mass or more, relative to 100% by mass of the non-volatile content of the epoxy resin (A), Particularly preferred is 70% by mass or more.

Among epoxy resins, there are epoxy resins that are liquid at a temperature of 20°C (hereinafter also referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter also referred to as "solid ring Oxygen resin"). In one embodiment, the resin composition layer 23 includes a liquid epoxy resin as the epoxy resin. In one embodiment, the resin composition layer 23 includes a solid epoxy resin as the epoxy resin. The resin composition layer 23 may include only a liquid epoxy resin as the epoxy resin, or may include only a solid epoxy resin as the epoxy resin, but is preferably a combination of a liquid epoxy resin and a solid epoxy resin And contains.

As a liquid epoxy resin, the liquid epoxy resin which has 2 or more epoxy groups in 1 molecule is preferable.

As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, Glycidylamine epoxy resin, phenol novolac epoxy resin, alicyclic epoxy resin with ester skeleton, cyclohexane epoxy resin, cyclohexane cyclohexane epoxy resin, epoxy Propylamine type epoxy resin and epoxy resin with butadiene structure.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC; "828US", "jER828EL" and " 825", "Epikote 828EL" (bisphenol A epoxy resin); "jER807" and "1750" (bisphenol F epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol phenolic resin) manufactured by Mitsubishi Chemical Corporation Varnish type epoxy resin); "630" and "630LSD" (glycidylamine epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ZX1059" (bisphenol A epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Mixed with bisphenol F epoxy resin); "EX-721" (glycidyl ester epoxy resin) manufactured by Nagase ChemteX; "Celloxide 2021P" (alicyclic with ester skeleton) manufactured by DAICEL Type epoxy resin); "PB-3600" manufactured by DAICEL, "JP-100" and "JP-200" manufactured by Soda Corporation of Japan (epoxy resin with butadiene structure); Nippon Steel & Sumikin Chemical Co., Ltd. "ZX1658", "ZX1658GS" (liquid 1,4-epoxypropyl cyclohexane type epoxy resin), etc. These systems can be used in one type alone or in combination of two or more types.

The solid epoxy resin is preferably a solid epoxy resin having 3 or more epoxy groups in one molecule, and more preferably an aromatic solid having 3 or more epoxy groups in one molecule状 epoxy resin.

As the solid epoxy resin, dixylenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolak type epoxy resin, and dicyclopentadiene type epoxy resin are preferred. Resin, triphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthyl ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type Epoxy resin, tetraphenylethane type epoxy resin.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resin) manufactured by DIC Resin); "N-690" (cresol novolac epoxy resin) made by DIC; "N-695" (cresol novolak epoxy resin) made by DIC; "HP- 7200" (dicyclopentadiene epoxy resin); "HP-7200HH", "HP-7200H", "EXA-4850-150", "EXA-7311", "EXA-7311-G3" manufactured by DIC ", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthyl ether type epoxy resin); "EPPN-502H" (triphenol type epoxy resin) manufactured by Nippon Kayaku ); "NC7000L" (naphthol novolak type epoxy resin) manufactured by Nippon Kayaku Corporation; "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Corporation ); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co.; "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin); "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Corporation Oxygen resin); "YX7700" (novolac epoxy resin containing xylene structure) manufactured by Mitsubishi Chemical Corporation; "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Company; "PG-500" manufactured by Mitsubishi Chemical Corporation "YL7760" (bisphenol AF type epoxy resin); "YL7800" manufactured by Mitsubishi Chemical Corporation (茀-type epoxy resin); "jER1010" manufactured by Mitsubishi Chemical Corporation (solid bisphenol A epoxy resin); Mitsubishi Chemical "JER1031S" (tetraphenylethane type epoxy resin) manufactured by the company. These systems can be used in one type alone or in combination of two or more types.

As the (A) epoxy resin, when a liquid epoxy resin and a solid epoxy resin are used in combination, the ratio of their amounts (liquid epoxy resin: solid epoxy resin) is expressed as a mass ratio, and is preferably 1:1 to 1:50, more preferably 1:3 to 1:30, particularly preferably 1:5 to 1:20. Since the ratio of the amount of the liquid epoxy resin to the solid epoxy resin is in such a range, the desired effect of the present invention can be significantly obtained.

The epoxy equivalent of the epoxy resin is preferably 50g/eq.～5000g/eq., more preferably 50g/eq.～3000g/eq., particularly preferably 80g/eq.～2000g/eq., and even more preferably 110g/eq.～1000g/eq. In this range, the crosslink density of the cured product of the resin sheet becomes sufficient, and an insulating layer with a small surface roughness can be formed. The epoxy equivalent is the mass of an epoxy resin containing 1 equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

(A) The weight average molecular weight (Mw) of the epoxy resin is preferably 100-5000, more preferably 250-3000, and particularly preferably 400-1500. The weight average molecular weight of the resin can be measured as a polystyrene conversion value by gel permeation chromatography (GPC).

When the (A) epoxy resin is contained in the resin composition layer 23, the content of the (A) epoxy resin is not particularly limited, but when the non-volatile content in the resin composition 23 is regarded as 100% by mass, it is preferable It is 1% by mass or more, more preferably 5% by mass or more, particularly preferably 10% by mass or more, and particularly preferably 15% by mass or more. The upper limit is preferably 60% by mass or less, more preferably 55% by mass or less, particularly preferably 50% by mass or less, and particularly preferably 45% by mass or less.

The curing agent (B) is not particularly limited as long as it has the function of curing epoxy resin. Examples include phenol curing agents, naphthol curing agents, acid anhydride curing agents, active ester curing agents, benzene And 㗁𠯤 series hardener, cyanate ester hardener and carbodiimide hardener. (B) The curing agent system may be used alone or in combination of two or more kinds.

As the phenol-based curing agent and the naphthol-based curing agent, from the viewpoint of heat resistance and water resistance, a phenol-based curing agent having a novolak structure or a naphthol-based curing agent having a novolak structure is preferable. Also, from the viewpoint of adhesion to the adherend, a nitrogen-containing phenol-based hardener or a nitrogen-containing naphthol-based hardener is preferred, and a phenol-based hardener containing a tri-skeleton or a tri-skeleton is more preferable The naphthol hardener. Among them, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a phenol novolak resin containing a tri-skeleton is preferred. Specific examples of phenol-based hardeners and naphthol-based hardeners include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Chemical Co., Ltd., and "NHN" manufactured by Nippon Kayaku Co., Ltd. ", "CBN", "GPH", "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. -495", "SN-375", "SN-395", "LA-7052", "LA-7054", "LA-3018", "LA-3018-50P", "LA-1356" manufactured by DIC ", "TD2090", "TD-2090-60M", etc.

Examples of acid anhydride hardeners include hardeners having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride hardeners include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Dicarboxylic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3- (Furyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, diphenyl ketone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene Tetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenyl tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro -5-(Tetrahydro-2,5-dioxo-3-furyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(trimellitic anhydride), styrene and Maleic acid copolymerized into styrene, maleic acid resin and other polymer type acid anhydrides. Examples of commercially available products of acid anhydride hardeners include "HNA-100" and "MH-700" manufactured by Nippon Rika Corporation.

There are no special restrictions on the active ester curing agent. Generally, it is better to use phenol esters, thiophenol esters, N-hydroxyamine esters, heterocyclic hydroxyl compound esters, etc. The reactivity is high in 1 molecule Compounds with more than two ester groups. The active ester curing agent is preferably obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxyl compound and/or a thiol compound. Particularly from the viewpoint of improving heat resistance, an active ester curing agent derived from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester curing agent derived from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred hardener. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of the phenol compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methyl Alkylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-Dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, dicyclopentadiene type diphenol compounds, phenol Novolac, etc. The "dicyclopentadiene type diphenol compound" referred to here refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

Specifically, it is preferably an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetate of a phenol novolak, and a benzyl containing a phenol novolak. Among the active ester compounds of the acetate, the active ester compound containing a naphthalene structure and the active ester compound containing a dicyclopentadiene type diphenol structure are more preferable. The so-called "dicyclopentadiene-type diphenol structure" refers to a bivalent structural unit formed by phenylene-dicyclopentene-phenylene.

As a commercially available product of an active ester hardener, among active ester compounds containing a dicyclopentadiene-type diphenol structure, "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", and " "HPC-8000H", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L", "EXB-8000L-65TM" (manufactured by DIC); among the active ester compounds containing naphthalene structure, Examples include "EXB9416-70BK" and "EXB-8150-65T" (manufactured by DIC Corporation); among the active ester compounds containing the acetate of phenol novolak, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be cited; Among the active ester compounds containing phenol novolac benzoate, "YLH1026" (manufactured by Mitsubishi Chemical Corporation) can be cited; among the active ester hardeners of phenol novolak acetate, "DC808 "(Manufactured by Mitsubishi Chemical Corporation); active ester-based hardeners for benzoic acid in phenol novolacs, including "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (Manufactured by Mitsubishi Chemical Corporation), etc.

As specific examples of the benzoic hardener, "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Co., Ltd.; "HFB2006M" manufactured by Showa Polymer Co., Ltd. and "HFB2006M" manufactured by Shikoku Chemical Industry Co., Ltd. Pd", "Fa", etc.

Examples of cyanate ester curing agents include bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4, 4'-methylene bis(2,6-dimethylphenyl cyanate), 4,4'-ethylene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2, 2-bis(4-cyanate ester)phenyl propane, 1,1-bis(4-cyanate ester phenylmethane), bis(4-cyanate ester-3,5-dimethylphenyl)methane, 1,3-Bis(4-cyanate phenyl-1-(methylethylene))benzene, bis(4-cyanate phenyl)sulfide and bis(4-cyanate phenyl)ether Such as bifunctional cyanate ester resins, polyfunctional cyanate ester resins derived from phenol novolac and cresol novolac, etc., and prepolymers of these cyanate ester resins that have been partially tri-formed. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (all-phenol novolak type polyfunctional cyanate resin) manufactured by LONZA Japan, "BA230", "BA230S75" (bisphenol A Part or all of the dicyanate is tripolymerized into a prepolymer, etc.

Specific examples of carbodiimide-based hardeners include "V-03" and "V-07" manufactured by Nisshinbo Chemical Co., Ltd., and the like.

When the hardener is included, the ratio of the amount of epoxy resin to hardener is expressed by the ratio of [total number of epoxy groups of epoxy resin]: [total number of reactive groups of hardener], preferably 1:0.2~ The range of 1:2 is more preferably 1:0.3 to 1:1.5, and particularly preferably 1:0.4 to 1:1.2. Here, the so-called reactive groups of the hardener are active hydroxyl groups, active ester groups, etc., which differ depending on the type of hardener. In addition, the total number of epoxy groups in epoxy resins is the value obtained by dividing the mass of the non-volatile components of each epoxy resin by the epoxy equivalent. The total value of all epoxy resins is the value of the hardener The total number of reactive groups is the value obtained by dividing the mass of the non-volatile components of each hardener by the equivalent of the reactive groups, which is the sum of all hardeners. Since the ratio of the amount of the epoxy resin to the hardener is in such a range, the heat resistance of the obtained hardened product is further improved.

When the (B) curing agent is contained in the resin composition layer 23, the content of the (B) curing agent is not particularly limited, but when the non-volatile content in the resin composition layer 23 is regarded as 100% by mass, it is preferably 0.1% by mass or more, more preferably 1% by mass or more, particularly preferably 3% by mass or more, and particularly preferably 5% by mass or more. The upper limit is preferably 45% by mass or less, more preferably 30% by mass or less, particularly preferably 25% by mass or less, and particularly preferably 20% by mass or less.

The resin composition layer 23 may further contain (C) an inorganic filler as an optional component.

(C) The material of the inorganic filler is not particularly limited, and examples include silica, alumina, glass, cordierite, silica, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, Hydrotalcite, diaspore, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, Magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate and zirconium tungstate phosphate, etc., particularly preferably silicon dioxide. Examples of silicon dioxide include amorphous silicon dioxide, fused silicon dioxide, crystalline silicon dioxide, synthetic silicon dioxide, and hollow silicon dioxide. In addition, as the silica, spherical silica is preferred. An inorganic filler system may be used individually by 1 type, and may be used in combination of 2 or more types.

(C) Commercial products of inorganic fillers include, for example, "UFP-30" manufactured by Denka Chemical Industry Co., Ltd.; "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumikin Materials Co., Ltd.; ADMATECHS Corporation "YC100C", "YA050C", "YA050C-MJE", "YA010C" manufactured by DENKA; "UFP-30" manufactured by DENKA; "Silfill NSS-3N", "Silfill NSS-4N", "Silfill" manufactured by TOKUYAMA NSS-5N"; "SC2500SQ", "SO-C4", "SO-C2", "SO-C1", etc. manufactured by ADMATECHS.

(C) The average particle size of the inorganic filler is preferably 30 μm or less, more preferably 20 μm or less, particularly preferably 15 μm or less, even more preferably 12 μm or less, and particularly preferably 10 μm or less. The lower limit of the average particle size of the inorganic filler is preferably 0.1 μm or more, more preferably 1 μm or more, particularly preferably 2 μm or more, and particularly preferably 2.5 μm or more. In particular, when used in the form of a resin sheet, it is preferably 2.5 μm or more. The average particle size of the inorganic filler can be measured by the laser diffraction and scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be created on a volume basis by a laser diffraction scattering particle size distribution measuring device, and the median particle size can be measured as the average particle size. For the measurement sample, 100 mg of the inorganic filler and 10 g of methyl ethyl ketone can be weighed in a vial and dispersed by ultrasonic for 10 minutes. For the sample to be measured, a laser diffraction type particle size distribution measuring device is used. The wavelength of the light source used is blue and red. The volume-based particle size distribution of the inorganic filler is measured by a flow cell method. For the diameter distribution, the average particle diameter is calculated as the median diameter. As a laser diffraction particle size distribution measuring device, for example, "LA-960" manufactured by Horiba Manufacturing Co., Ltd. can be cited.

From the standpoint of improving moisture resistance and dispersibility, (C) the inorganic filler is preferably aminosilane coupling agent, epoxysilane coupling agent, mercaptosilane coupling agent, alkoxysilane compound, Treated with one or more surface treatment agents such as organosilazane compound and titanate coupling agent. Commercial products of surface treatment agents include, for example, "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM803" (3-mercaptopropane) manufactured by Shin-Etsu Chemical Co., Ltd. Trimethoxysilane), "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM573" (N-phenyl-3-aminopropyl trimethyl) manufactured by Shin-Etsu Chemical Co., Ltd. Oxysilane), "SZ-31" (hexamethylsilazane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and KBM-4803 manufactured by Shin-Etsu Chemical Co., Ltd. "(Long-chain epoxy silane coupling agent), "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., etc.

The degree of surface treatment by the surface treatment agent is preferably within a specified range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated by 0.2 parts by mass to 5 parts by mass of the surface treatment agent, more preferably by 0.2 parts by mass to 3 parts by mass, and particularly preferably by 0.3 parts by mass Parts ~ 2 parts by mass for surface treatment.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler, from the viewpoint of improving the dispersibility of the inorganic filler, is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and particularly preferably 0.2 mg/ m ² or more. On the other hand, from the viewpoint of preventing the melt viscosity of the resin varnish and the melt viscosity of the sheet form from increasing, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and particularly preferably 0.5 mg/m ² or less.

(C) The amount of carbon per unit surface area of the inorganic filler can be measured after washing the surface-treated inorganic filler with a solvent (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the carbon content per unit surface area of the inorganic filler can be measured using a carbon analyzer. As a carbon analyzer, "EMIA-320V" manufactured by Horiba Manufacturing Co., Ltd. can be used.

(C) The specific surface area of the inorganic filler is preferably 1 m ² /g or more, more preferably 1.5 m ² /g or more, and particularly preferably ² m ² /g or more. The upper limit is not particularly limited, but it is preferably 50 m ² /g or less, 45 m ² /g or less, or 40 m ² /g or less. The specific surface area of the inorganic filler is based on the BET method, using a specific surface area measuring device (Macsorb HM-1210 manufactured by MOUNTECH), adsorbing nitrogen on the sample surface, and calculating the specific surface area using the BET multipoint method.

When the (C) inorganic filler is contained in the resin composition layer 23, the content of the (C) inorganic filler is not particularly limited. When the non-volatile content in the resin composition 23 is regarded as 100% by mass, it is preferably 1% by mass or more, more preferably 10% by mass or more, particularly preferably 30% by mass or more, particularly preferably 50% by mass or more. The upper limit is preferably 90% by mass or less, more preferably 85% by mass or less, particularly preferably 80% by mass or less, and particularly preferably 75% by mass or less.

The resin composition layer 23 may further contain (D) a thermoplastic resin as an optional component.

(D) Thermoplastic resins include, for example, phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyimide resins, polyimide resins, and polyether amide resins. Amine resin, polyether ketone resin, polyether sulfide resin, polyphenylene ether resin, polycarbonate resin, polyether ether ketone resin, polyester resin, etc. Among them, phenoxy resin is preferred. Moreover, a thermoplastic resin system may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of phenoxy resins include those having a skeleton selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, novolac skeleton, biphenyl skeleton, stilbene skeleton, and dicyclopentane A phenoxy resin with one or more types of skeletons consisting of an alkene skeleton, a norbornene skeleton, a naphthalene skeleton, an anthracene skeleton, adamantane skeleton, a terpene skeleton, and a trimethylcyclohexane skeleton. The terminal system of the phenoxy resin may be any functional group such as a phenolic hydroxyl group and an epoxy group.

As specific examples of phenoxy resins, "1256" and "4250" (both phenoxy resins containing bisphenol A skeleton) manufactured by Mitsubishi Chemical Corporation; "YX8100" manufactured by Mitsubishi Chemical Corporation (containing bisphenol S-frame phenoxy resin); "YX6954" (phenoxy resin containing bisphenol acetophenone skeleton) manufactured by Mitsubishi Chemical Corporation; "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; Mitsubishi Chemical "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7553", "YL7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", and "YL7482" manufactured by the company.

Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, and polyvinyl butyral resins are preferred. Specific examples of polyvinyl acetal resins include "Denka butyral 4000-2", "Denka butyral 5000-A", "Denka butyral 6000-C", and "Denka butyral 6000-EP" manufactured by Denka Chemical Industry Co., Ltd. ; S-LEC BH series, BX series (such as BX-5Z), KS series (such as KS-1), BL series, BM series, etc. manufactured by Sekisui Chemical Industry Company.

As a specific example of the polyimide resin, "Rikacoat SN20" and "Rikacoat PN20" manufactured by Nippon Rika Co., Ltd. can be cited. As a specific example of the polyimide resin, a linear polyimide obtained by reacting a bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (Japanese Patent Application Publication No. 2006-37083) Modification of polyimide described in the publication), polyimide containing a polysiloxane skeleton (polyimide described in JP 2002-12667 and JP 2000-319386), etc. Polyimide.

Specific examples of polyimide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. As specific examples of polyimide resins, modified polyimides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyimide imide) manufactured by Hitachi Chemical Co., Ltd. Imine.

As a specific example of the polyether sulfide resin, "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. can be cited.

As a specific example of the polyphenylene ether resin, an oligomeric phenylene ether and styrene resin "OPE-2St 1200" manufactured by Mitsubishi Gas Chemical Co., Ltd. can be cited.

As a specific example of the polymer resin, the polymer "P1700" and "P3500" manufactured by Solvay Advanced Polymers can be cited.

(D) The weight average molecular weight (Mw) of the thermoplastic resin is preferably 8,000 or more, more preferably 10,000 or more, particularly preferably 20,000 or more, and preferably 70,000 or less, more preferably 60,000 or less, particularly preferably 50,000 or less.

(D) The content of the thermoplastic resin, when the non-volatile content in the resin composition is regarded as 100% by mass, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, and more It is preferably 5% by mass or less, more preferably 3% by mass or less, and particularly preferably 2% by mass or less.

When the (D) thermoplastic resin is contained in the resin composition layer 23, the content of the (D) thermoplastic resin is not particularly limited, but when the non-volatile content in the resin composition layer 23 is regarded as 100% by mass, it is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, and particularly preferably 1.5% by mass or more. The upper limit is preferably 20% by mass or less, more preferably 10% by mass or less, particularly preferably 5% by mass or less, and particularly preferably 2% by mass or less.

The resin composition layer 23 may further contain (E) a flame retardant as an optional component.

(E) Flame retardants include, for example, phosphazene compounds, organophosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, silicone-based flame retardants, metal hydroxides, etc. It is a phosphazene compound. The flame retardant system may be used individually by 1 type, or may use 2 or more types together.

The phosphazene compound is not particularly limited as long as it is a cyclic compound containing nitrogen and phosphorus as constituent elements, but the phosphazene compound is preferably a phosphazene compound having a phenolic hydroxyl group.

Specific examples of phosphazene compounds include "SPH-100", "SPS-100", "SPB-100" and "SPE-100" manufactured by Otsuka Chemical Co., Ltd., and "FP-100" manufactured by Fushimi Pharmaceutical Co., Ltd. ", "FP-110", "FP-300", "FP-400", etc., preferably "SPH-100" manufactured by Otsuka Chemical Co., Ltd.

As the flame retardant other than the phosphazene compound, commercially available products can be used, for example, "HCA-HQ" manufactured by Sanko Co., Ltd., "PX-200" manufactured by Dahachi Chemical Industry Co., Ltd., and the like. The flame retardant is preferably one that is not easily hydrolyzed, for example, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and the like are preferred.

When the (E) flame retardant is contained in the resin composition layer 23, the content of the (E) flame retardant is not particularly limited, but when the non-volatile content in the resin composition layer 23 is regarded as 100% by mass, it is more It is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and particularly preferably 1% by mass or more. The upper limit thereof is preferably 4% by mass or less, more preferably 3% by mass or less, particularly preferably 2% by mass or less, and particularly preferably 1.5% by mass or less.

The resin composition layer 23 may further contain (F) a hardening accelerator as an optional component.

(F) Hardening accelerators include, for example, phosphorus hardening accelerators, amine hardening accelerators, imidazole hardening accelerators, guanidine hardening accelerators, metal hardening accelerators, and the like. Among them, phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, and metal-based curing accelerators are preferred, and phosphorus-based curing accelerators and imidazole-based curing accelerators are more preferred. The hardening accelerator system may be used alone or in combination of two or more types.

Examples of phosphorus-based hardening accelerators include triphenyl phosphine, boric acid phosphonium compounds, tetraphenyl phosphonium tetraphenyl borate, butyl phosphonium tetraphenyl borate, tetrabutyl phosphonium decanoate, (4- (Methylphenyl) triphenyl phosphonium thiocyanate, tetraphenyl phosphonium thiocyanate, butyl triphenyl phosphonium thiocyanate, methyl tributyl phosphonium dimethyl phosphate, etc.

Examples of amine-based hardening accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine (DMAP), benzyldimethylamine, 2,4,6, -Ginseng (dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc.

Examples of imidazole-based hardening accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-ethyl-4-methylimidazole , 1,2-Dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1 -Benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4 -Methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazole Onium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-tris, 2,4-diamino-6- [2'-Undecylimidazolyl-(1')]-ethyl-s-tris, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-( 1')]-ethyl-s-tris, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-tris isocyanuric acid Adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-Dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2 -Imidazole compounds such as phenylimidazoline and adducts of imidazole compounds and epoxy resin.

As the imidazole-based hardening accelerator, commercially available products may also be used, and examples include "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Examples of guanidine-based hardening accelerators include cyanoguanidine, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, and dimethylguanidine. Guanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1, 5,7-Triazabicyclo[4.4.0]dec-5-ene, 1-methyl biguanide, 1-ethyl biguanide, 1-n-butyl biguanide, 1-n-octadecyl biguanide, 1,1- Dimethyl biguanide, 1,1-diethyl biguanide, 1-cyclohexyl biguanide, 1-allyl biguanide, 1-phenyl biguanide, 1-(o-tolyl) biguanide, etc.

Examples of metal-based hardening accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt acetone (II) and cobalt acetone (III), and organic copper complexes such as copper acetone (II). , Organic zinc complexes such as zinc acetone (II), organic iron complexes such as iron (III) acetone, organic nickel complexes such as nickel (II) acetone, manganese acetone (II) and other organic manganese complexes. Examples of organic metal salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, zinc stearate, and the like.

When the (F) hardening accelerator is contained in the resin composition layer 23, the content of the (F) hardening accelerator is not particularly limited, but when the non-volatile content in the resin composition layer 23 is regarded as 100% by mass, it is more It is preferably 0.001 mass% or more, more preferably 0.01 mass% or more, particularly preferably 0.05 mass% or more, and particularly preferably 0.1 mass% or more. The upper limit is preferably 3% by mass or less, more preferably 2% by mass or less, particularly preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

The resin composition layer 23 may further include an organic filler, an elastomer, a tackifier, a defoamer, a leveling agent, an adhesion imparting agent, a polymerization initiator, etc. as optional components. These components can be used individually by 1 type, and can also be used in combination of 2 or more types. The content of each can be set appropriately as long as it belongs to the industry.

The minimum melt viscosity of the resin composition layer 23 is preferably 50 poise or more, more preferably 100 poise or more, particularly preferably 500 poise or more, and particularly preferably 1,000 poise from the viewpoint of remarkably obtaining the desired effect of the present invention. the above. The upper limit of the minimum melt viscosity of the resin composition layer 23 is preferably 50,000 poise or less, more preferably 25,000 poise or less, particularly preferably 10,000 poise or less, and particularly preferably 5,000 poise or less.

The thickness of the resin composition layer 23 before lamination is not particularly limited as long as it is within the range that can exhibit the desired effects of the present invention, but it is preferably 1 μm or more, more preferably 3 μm or more, and particularly preferably 5 μm or more , Particularly preferably 7μm or more. The upper limit of the thickness is not particularly limited as long as the desired effect of the present invention is exhibited. However, it is preferably 150 μm or less, more preferably 100 μm or less, particularly preferably 50 μm or less, and particularly preferably 30 μm or less.

The resin sheet 20 may include any layers other than the support 21, the release layer 22, and the resin composition layer 23 as necessary. Examples of the optional layer include a protective film corresponding to a support provided on the surface of the resin composition layer 23 that is not bonded to the release layer 22. The protective film is an arbitrary configuration that is peeled off before lamination. By using the protective film, adhesion or damage of dust and the like to the surface of the resin composition layer 23 can be suppressed.

As the protective film, for example, a film made of a plastic material is preferable, and as the plastic material, the same as those exemplified as the material of the support 21 can be mentioned.

Moreover, as a protective film, the protective film with a mold release layer which has a mold release layer on the surface joined with the resin composition layer 23 can also be used. As the mold release agent used for the mold release layer of the protective film with a mold release layer, the same thing as the mold release agent used for the mold release layer of the support body with a mold release layer is mentioned, for example.

The thickness of the protective film is not particularly limited, but it is preferably 1 μm or more, more preferably 5 μm or more, particularly preferably 10 μm or more, even more preferably 15 μm or more, and particularly preferably 20 μm or more. The upper limit of the thickness of the protective film is not particularly limited, but is preferably 75 μm or less, more preferably 60 μm or less, particularly preferably 50 μm or less, and particularly preferably 40 μm or less. In addition, when a protective film with a release layer is used, the thickness of the entire protective film with a release layer is preferably in the above-mentioned range. In addition, the adhesive force between the resin composition layer 23 and the protective film is preferably smaller than the adhesive force between the release layer 22 and the support 21.

The method of manufacturing the resin sheet is not particularly limited as long as it is a method capable of manufacturing the resin sheet 20 including the resin composition layer 23 and the release layer 22 and the support 21 if necessary. For example, the following description may be mentioned. One method and the second method.

In the first method, the resin sheet can be manufactured, for example, by a method including the following steps, (A1) On the support 21, for example, by using a die coater or the like to apply a resin varnish containing the components of the release layer 22 (a varnish refers to a coating liquid containing each resin component and an arbitrary organic solvent, the same applies below), Drying to form the release layer 22, and the step of preparing a temporary resin sheet with a support, and (A2) On the release layer 22 of the temporary resin sheet with support, for example, by using a die coater or the like, a resin varnish containing the components of the resin composition layer 23 is applied and dried to form the resin composition layer 23, and The step of obtaining the resin sheet 20.

In the first method, after step (A2), (A3) a step of attaching a protective film to the resin composition layer 23 of the resin sheet 20 may be further included. Furthermore, in the first method, after step (A3), the step (A4) of removing the protective film may be further included.

In the second method, the resin sheet can be manufactured, for example, by a method including the following steps, (B1) A step of preparing a temporary resin sheet with a support by coating a resin varnish containing the components of the release layer 22 on the support 21, for example, by using a die coater or the like, and drying to form the release layer 22, (B2) A step of preparing a temporary resin sheet with a protective film by applying a resin varnish containing the components of the resin composition layer 23 on the protective film and drying to form the resin composition layer 23 ,and (B3) A step of joining a temporary resin sheet with a support and a temporary resin sheet with a protective film to obtain a resin sheet 20 with a protective film.

In the second method, further after step (B3), a step (B4) of removing the protective film may be included.

Examples of organic solvents that may be contained in the resin varnish include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, serosol acetate, propylene glycol monomethyl Ester solvents such as ether acetate, carbitol acetate, ethyl diethylene glycol acetate, etc.; carbitol solvents such as serosol and butyl carbitol; benzene, toluene, xylene, ethyl Aromatic hydrocarbon solvents such as benzene and mesitylene; Amine solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone; methanol, ethanol, 2-methyl Alcohol-based solvents such as oxypropanol; hydrocarbon-based solvents such as cyclohexane. The organic solvent system may be used alone or in combination of two or more kinds.

The drying system can be performed by well-known methods such as heating and blowing hot air. The drying conditions are not particularly limited, but the content of the organic solvent in the resin composition layer 23 or the release layer 22 is 10% by mass or less, preferably 5% by mass or less, and more preferably 1% by mass or less. dry. Although it also varies with the boiling point of the organic solvent in the resin varnish, for example, when a resin varnish containing 10% by mass to 60% by mass of an organic solvent is used, it can be dried at 50℃～150℃ for 1 minute～10 Minutes, and the resin composition layer 23 or the release layer 22 is formed.

The resin sheet 20 can be wound into a roll and stored. When the resin sheet has a protective film, it can be used by peeling off the protective film.

<Step (2)> Step (2) is a step of preparing the circuit board 10 having the substrate 12 and the circuit layer 11. As shown in FIG. 1, the circuit board 10 includes a substrate 12 and a circuit layer 11 having an arbitrary circuit pattern on a part of its surface.

The conductive material used for the circuit layer 11 is not particularly limited. In a suitable embodiment, the circuit layer includes at least one selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium Of metal. The circuit layer may be a single metal layer or an alloy layer. As the alloy layer, for example, an alloy composed of two or more metals selected from the above group (such as nickel-chromium alloy, copper-nickel alloy and copper -Titanium alloy) formed. Among them, from the viewpoints of versatility of circuit layer formation, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper is preferred, or The alloy layer of nickel-chromium alloy, copper-nickel alloy, copper-titanium alloy, more preferably a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy alloy The layer is preferably a single metal layer of copper.

The line (line width)/space (width between lines) ratio of the circuit layer 11 is not particularly limited, but it is preferably 20/20μm or less (that is, the pitch is 40μm or less), and more preferably 18/18μm or less (the pitch is 36μm Below), more preferably 15/15 μm or less (pitch 30 μm or less). The lower limit of the line/space ratio of the circuit layer 11 is not particularly limited, but is preferably 0.5/0.5 μm or more, and more preferably 1/1 μm or more. The pitch is not necessarily the same in the entire circuit layer 11. The minimum pitch of the circuit layer 11 can be 40 μm or less, 36 μm or less, or 30 μm or less.

In the step (3) described below, the area ratio of the circuit layer 11 formed on the surface of the substrate 12 in the range of the laminated resin sheet 20 is not particularly limited, but it is preferably 1% or more, more preferably 5 % Or more, more preferably 10% or more, particularly preferably 20% or more. The upper limit of the area ratio is not particularly limited, but it is preferably 80% or less, more preferably 60% or less, particularly preferably 50% or less, and particularly preferably 40% or less.

The thickness of the circuit layer 11 depends on the desired design of the circuit layer 11, but it is preferably 1 μm or more, more preferably 5 μm or more, particularly preferably 10 μm or more, and particularly preferably 15 μm or more. The upper limit of the thickness of the circuit layer 11 is not particularly limited, but it is preferably 35 μm or less, more preferably 30 μm or less, particularly preferably 25 μm or less, and particularly preferably 20 μm or less.

The substrate 12 is not particularly limited. Examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, and the like. A metal layer such as copper foil can be formed on the surface of the substrate.

<Step (3)> Step (3) is a step of laminating the resin sheet 20 on the circuit board 10 so that the circuit layer 11 penetrates the resin composition layer 23 and reaches the peeling layer 22.

The lamination of the resin sheet 20 to the circuit board 10 in step (3) is usually carried out by crimping the resin sheet 20 to the circuit board 10, specifically, for example, laminating with a laminating device, etc., if necessary It is performed by pressing with a flat pressing device or the like. The pressure during lamination is not particularly limited, but is preferably in the range of 0.1 MPa to 1.8 MPa, more preferably in the range of 0.3 MPa to 1.5 MPa. The pressing time during lamination is not particularly limited, but it is preferably in the range of 5 seconds to 400 seconds, and more preferably in the range of 10 seconds to 300 seconds.

In addition, from the viewpoint of contributing to the improvement of the fluidity of the resin and sufficient filling, the lamination is preferably performed while heating. The heating temperature during lamination is not particularly limited, but is preferably 60°C or higher, more preferably 80°C or higher, and particularly preferably 100°C or higher. The upper limit of the heating temperature during lamination is not particularly limited, but it is preferably 180°C or lower, more preferably 160°C or higher, and particularly preferably 140°C or lower.

In the laminating device, a roll type, a film type, etc. are known. From the viewpoint of reducing bubbles and embedding defects, the film type that can be pressurized with a uniform pressure is preferred. By lamination through the membrane with uniform pressure, the occurrence of bubbles or wrinkles in the resin composition layer can be suppressed. In addition, the laminating device is preferably a vacuum pressure laminator equipped with pressure reducing means. By laminating under vacuum, the occurrence of bubbles or wrinkles in the resin composition layer can be suppressed. The pressure at the time of decompression is not particularly limited. For example, it can be set at 50 hPa or less, 20 hPa or less, 15 hPa or less, 13 hPa or less.

In addition, from the viewpoint of contributing to the improvement of the fluidity of the resin and sufficient filling, the laminating device is preferably provided with a sheet presser capable of uniform heating.

The pressurization of the flattening pressing device is performed when the final target is a build-up multilayer circuit board, etc., when flattening is required for further build-up in the subsequent steps. At this time, the flat pressing device includes a metal plate as a pressing means.

The pressure at the time of pressurization of the flat press device is not particularly limited, but is preferably in the range of 0.2 MPa to 2 MPa, more preferably in the range of 0.5 MPa to 3 MPa. The pressing time during pressing of the flat pressing device is not particularly limited, but is preferably in the range of 5 seconds to 400 seconds, more preferably in the range of 10 seconds to 300 seconds.

From the viewpoint of contributing to the improvement of the fluidity of the resin, the pressing by the flat pressing device is preferably performed while heating. The heating is preferably performed by heating a metal plate. The heating temperature of the metal plate can be set in the same manner as the lamination of the laminating device. The pressing by the flat pressing device is preferably not to directly press the metal plate to the resin sheet 10, but to press through a buffer material such as heat-resistant rubber. The pressing of the flat pressing device may be continuously performed after the lamination of the laminating device.

In one embodiment, the thickness of the release layer 22 before lamination is regarded as A (μm), the thickness of the resin composition layer 23 before lamination is regarded as B (μm), and the height of the circuit layer 11 is regarded as C( μm), when the area ratio of the circuit layer 11 formed with respect to the substrate 12 surface in the range of the laminated resin sheet 20 in the step (3) is taken as D (%), it is from the suppression of bubbles or wrinkles in the resin composition layer From the viewpoint of occurrence, the relationship of (A+B)/{C×(1-0.01×D)}>1 is better, and (A+B)/{C×(1-0.01×D) }>1.1 relationship. In addition, in the step (4) described below, from the viewpoint of exposing a part of the circuit layer appropriately, the relationship of B/{C×(1-0.01×D)}<1.2 is more preferable, and more preferable It becomes a relationship of B/{C×(1-0.01×D)}<1.0, and a relationship of B/{C×(1-0.01×D)}<0.9 is particularly preferable. On the other hand, from the viewpoint of fully exerting the side support function of the resin composition layer (hardened body layer), the relationship of B/{C×(1-0.01×D)}>0.1 is more preferable, and B The relationship of /{C×(1-0.01×D)}>0.3, especially the relationship of B/{C×(1-0.01×D)}>0.4, the relationship of B/{C×(1-0.01) ×D)}>0.5.

3 is a cross-sectional view schematically showing a laminated circuit board 100 obtained by laminating a resin sheet 20 on the circuit board 10 in one embodiment. As shown in FIG. 3, after the resin sheet 20 is laminated, in the portion where the circuit layer 111 is not formed, a resin composition layer 123, a release layer 122, and a support 121 are sequentially laminated on the board 112, and the circuit layer 111 is It penetrates the resin composition layer 123 and reaches the peeling layer 122.

<Step (4)> Step (4) is a step of removing the peeling layer 122 of the build-up circuit board 100 to expose a part of the circuit layer 111. As a method of removing the peeling layer 122, a peeling removal method of peeling off the peeling layer 122 directly, a dissolving removal method of dissolving the peeling layer 122 with a specific solution, a method of removing the peeling layer 122 by plasma treatment, and the like can be mentioned. When the support 121 exists in the build-up circuit board 100, the support 121 can be removed simultaneously with the peeling layer 122 in this step. In the step (6) described below, the support 121 can be removed in advance.

The peeling and removal of the peeling layer 122 can be performed by, for example, peeling off a part of the end of the peeling layer 122, grasping a part of the end with a clamp, and directly tearing the peeling layer 122. The peeling strength of the peeling layer 122 when the peeling layer 122 is peeled off is preferably 500 gf/cm or less, more preferably 300 gf/cm or less, and particularly preferably 200 from the viewpoint of the ease of peeling of the peeling layer 122 gf/cm or less, particularly preferably 100 gf/cm or less. The lower limit of the peel strength of the peeling layer 122 is preferably 1 gf/cm or more, more preferably 2 gf/cm or more, 3 gf/cm or more, and 5 gf/0m or more from the viewpoint of suppressing the natural peeling of the peeling layer 122 . The peel strength of the peeling layer 122 can be peeled off one end of the peeling layer 122 and grasped with a clamp. At room temperature, the peeling layer 122 is torn at a speed of 50mm/min in the vertical direction by 35mm, and the load at that time (gf/cm) is measured. By.

The dissolution and removal of the peeling layer 122 can be performed by contacting the peeling layer 122 with a specific solution capable of dissolving the peeling layer 122 under specific conditions. The specific solution and conditions that can dissolve the peeling layer 122 can be appropriately selected and set by the person in charge. In one embodiment, the dissolution and removal of the peeling layer 122 can be performed as a wet roughening treatment of the build-up circuit board 100. At this time, when a through hole or the like exists in the build-up circuit board 100, the removal of the scum may also be performed at the same time. As an example of the wet roughening treatment, a method of sequentially performing the swelling treatment of the swelling liquid, the roughening treatment of the oxidizing agent, and the neutralization treatment of the neutralization liquid can be given.

The swelling liquid is not particularly limited, and examples include an alkali solution, a surfactant solution, and the like. An alkali solution is preferred, and the alkali solution is more preferably a sodium hydroxide solution or a potassium hydroxide solution. Examples of commercially available swelling fluids include Swelling Dip Securiganth P, Swelling Dip Securiganth SBU manufactured by ATOTECH Japan Co., Ltd. and the like.

The swelling treatment system of the swelling liquid is not particularly limited. For example, it can be performed by immersing in the swelling liquid at 30°C to 90°C for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin to an appropriate level, it is preferable to immerse in a swelling liquid at 40°C to 80°C for 5 seconds to 15 minutes.

The oxidizing agent is not particularly limited. For example, an alkaline permanganic acid solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide is mentioned.

The roughening treatment by an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the peeling layer 122 in an oxidizing agent solution heated to 60°C to 80°C for 10 minutes to 30 minutes. In addition, the concentration of permanganate in the alkaline permanganic acid solution is preferably 5% by mass to 10% by mass. As a commercially available oxidant, for example, alkaline permanganic acid solutions such as Concentrate Compact P, Dosing Solution Securiganth P manufactured by Atotech Japan Co., Ltd. can be cited.

The neutralizing liquid is preferably an acidic aqueous solution, and as a commercially available product, for example, Reduction solution Securiganth P manufactured by Atotech Japan Co., Ltd. can be cited.

The treatment of the neutralization liquid can be performed by immersing the treated surface roughened by the oxidizing agent solution in a neutralization liquid at 30°C to 80°C for 5 minutes to 30 minutes. From the viewpoint of workability and the like, a method of immersing the object roughened by the oxidizing agent solution in a neutralization solution at 40°C to 70°C for 5 minutes to 20 minutes is preferred.

The removal of the peeling layer 122 by the plasma treatment is performed by delivering the plasma treatment under the condition that the peeling layer 122 can be removed. The conditions under which the peeling layer 122 can be removed can be appropriately set as long as it is a professional. In one embodiment, the removal of the peeling layer 122 by plasma treatment can be performed as a dry roughening treatment of the build-up circuit board 100. At this time, when a through hole or the like exists in the build-up circuit board 100, the removal of the scum may also be performed at the same time.

The dry roughening treatment system using plasma can be implemented using a commercially available plasma desmear treatment device. Among the commercially available plasma desmear treatment devices, microwave plasma devices made by NISSIN, and atmospheric plasma etching devices made by Sekisui Chemical Industry Co., Ltd. can be suitably used.

As the dry roughening treatment, a dry sandblasting treatment in which an abrasive can be sprayed from a nozzle to polish the treatment target can also be used. The dry blast treatment system can be implemented using a commercially available dry blast treatment device. When water-soluble abrasives are used as abrasives, the abrasives do not remain inside the via holes by washing with water after the dry sandblasting treatment, and the scum can be effectively removed.

Fig. 4 schematically shows a cross-sectional view of the laminated circuit board 100' after the support 121 and the peeling layer 122 are removed in one embodiment. As shown in FIG. 4, after the peeling layer 122 is removed, a part of the circuit layer 111 is exposed on the surface of the resin composition layer 123.

<Step (5)> The manufacturing method of the laminated circuit board of the present invention preferably includes after step (3) and before step (4), or after step (4), further comprising (5) hardening the resin composition layer 123 into a hardened body layer step. The curing conditions of the resin composition layer 123 are not particularly limited. When the resin composition layer 123 contains a thermosetting resin, it can be thermally cured by heating to form a cured body layer.

For example, although the thermosetting conditions of the resin composition layer 123 also vary depending on the type of resin composition, etc., the curing temperature can usually be set in the range of 120°C to 240°C (preferably in the range of 150°C to 220°C, more It is preferably in the range of 170°C to 200°C), and the curing time can usually be set in the range of 5 minutes to 120 minutes (preferably 10 minutes to 100 minutes, more preferably 15 minutes to 90 minutes).

Before the resin composition layer 123 is thermally cured, the resin composition layer 123 may be preliminarily heated at a temperature lower than the curing temperature. For example, before the resin composition layer 123 is thermally cured, it can be prepared at a temperature of usually 50°C or more and less than 120°C (preferably 60°C or more and 115°C or less, more preferably 70°C or more and 110°C or less). The heating of the resin composition layer 123 is usually 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, particularly preferably 15 minutes to 100 minutes).

<Step (6)> The manufacturing method of the laminated circuit board of the present invention is that when the resin sheet 120 has the support 121 and the support 121 is not removed together with the release layer 122 in the step (4), it is preferably after the step (3) and the step (4). ) Before, further comprising (5) the step of removing the support 121. The method of removing the support 121 is not particularly limited, and for example, a peeling removal method in which the support 121 is directly peeled off can be mentioned. The peeling and removal of the support 121 can be performed by, for example, peeling off a part of the end of the support 121, grasping the end with a clamp, and then directly tearing the support 121.

In the laminated circuit board obtained by the manufacturing method of the present invention, since the circuit layer is laterally supported by the resin composition layer (hardened body layer), the occurrence of damage to the circuit layer 11 during soldering can be suppressed.

＜Semiconductor device＞ The multilayer circuit board of the present invention can be used in general semiconductor devices. Examples of semiconductor devices provided with the multilayer circuit board of the present invention include those used in electrical products (such as computers, mobile phones, digital cameras, and televisions, etc.) and vehicles (such as locomotives, automobiles, trams, ships, and aircraft, etc.). Various semiconductor devices. [Example]

Hereinafter, the present invention will be explained in more detail with examples. The present invention is not limited by these embodiments. In addition, in the following, the "parts" and "%" that indicate the amount respectively mean "parts by mass" and "% by mass" unless otherwise specified.

<Production example 1-A: Production of peeling layer A> 20 parts of hydroxypropyl methylcellulose phthalate (hydroxypropyl methylcellulose phthalate) (HP-55 manufactured by Shin-Etsu Chemical Co., Ltd.) was heated and dissolved in 40 parts of methyl ethyl ketone And 40 parts of cyclohexanone to prepare a resin varnish, apply it on a PET film with a release layer as a support ("PET501010" manufactured by LINTEC Co., Ltd., thickness 38μm), and heat at 100°C for 4 minutes to obtain a 5μm Peel layer A.

Furthermore, 25 sheets of peeling layer A were laminated to form a 1 mm thick adhesive film and punched out to a diameter of 20 mm to prepare a measurement sample. For the prepared measurement sample, use a dynamic viscoelasticity measuring device ("Rheogel-G3000" manufactured by UBM) at a heating rate of 5°C/min, a measurement temperature interval of 2.5°C, a measurement temperature range of 60 to 180°C, and vibration frequency The lowest melt viscosity is measured under the measuring conditions of 1Hz. Became the value of more than 20,000 poise.

<Production example 1-B: Production of peeling layer B> 10 parts of polyvinyl acetal resin (BX-5Z manufactured by Sekisui Chemical Co., Ltd.) was heated and dissolved in 45 parts of methyl ethyl ketone and 45 parts of cyclohexanone to prepare a resin varnish, which was applied to the mold release layer as a support The PET film (“PET501010” manufactured by LINTEC Co., Ltd., thickness 38 μm) was heated at 100° C. for 4 minutes to obtain a release layer B of 5 μm. The lowest melt viscosity was measured by the same method as in Production Example 1-A, and the result was a value exceeding 20,000 poise.

<Production example 1-C: Production of peeling layer C> A 15% MEK solution of polyacrylic resin (TEISANRESIN SG-P3 manufactured by Nagase ChemteX) was applied to a PET film with a mold release layer as a support (“PET501010” manufactured by LINTEC Co., Ltd., thickness 38μm), It heated at 100 degreeC for 4 minutes, and obtained the peeling layer C of 5 micrometers. The lowest melt viscosity was measured by the same method as in Production Example 1, and the result was a value exceeding 20,000 poise.

<Production example 1-D: Production of peeling layer D> A 25% aqueous solution of solid content of a water-soluble polyester resin (Z-446 manufactured by Interchange Chemical Co., Ltd.) was applied to a PET film with a release layer as a support ("PET501010" manufactured by LINTEC Co., Ltd., thickness 38μm) , Heating at 100°C for 10 minutes to obtain a peeling layer D of 5 μm. The lowest melt viscosity was measured by the same method as in Production Example 1-A, and the result was a value exceeding 20,000 poise.

<Production example 1-E: Production of peeling layer E> 5 parts of polyvinyl acetal resin (BX-5Z manufactured by Sekisui Chemical Co., Ltd.), 8 parts of flexible epoxy resin (epoxy equivalent 450, EXA-4850-150 manufactured by DIC Corporation), and bisphenol A epoxy resin ( Epoxy equivalent 180, "jER828EL" manufactured by Mitsubishi Chemical Corporation) 7 parts, solid content 60 of a phenolic hardener containing a tri-framework (hydroxy equivalent of 125, "LA7054" manufactured by DIC (Stock), nitrogen content about 12% by mass) 10 parts of MEK solution of mass% is heated and dissolved in 40 parts of methyl ethyl ketone and 40 parts of cyclohexanone to make a resin varnish, which is applied as a support to a PET film with a release layer (made by LINTEC (stock) PET501010", thickness 38μm), heated at 100°C for 4 minutes to obtain a peeling layer E of 5μm. The lowest melt viscosity was measured by the same method as in Production Example 1-A, and the result was a value exceeding 20,000 poise.

<Production example 1-F: Production of peeling layer F> 3 parts of polyvinyl acetal resin (BX-5Z manufactured by Sekisui Chemical Co., Ltd.), 8 parts of flexible epoxy resin (epoxy equivalent 450, EXA-4850-150 manufactured by DIC), and bisphenol A epoxy resin ( Epoxy equivalent 180, Mitsubishi Chemical Corporation "jER828EL") 9 parts, three-framed phenolic hardener (hydroxyl equivalent 125, DIC (stock) "LA7054", nitrogen content about 12% by mass) solid content 60 10 parts by mass of MEK solution was heated and dissolved in 40 parts of methyl ethyl ketone and 40 parts of cyclohexanone to prepare a resin varnish, which was coated on a PET film with a release layer as a support (manufactured by LINTEC (stock) PET501010", thickness 38 μm), heated at 100°C for 4 minutes to obtain a peeling layer F of 5 μm. The lowest melt viscosity was measured in the same manner as in Production Example 1-A, and the result was 12,000 poise.

<Production example 1-G: Production of peeling layer G> 2 parts of polyvinyl acetal resin (BX-5Z manufactured by Sekisui Chemical Co., Ltd.), 6 parts of flexible epoxy resin (epoxy equivalent 450, EXA-4850-150 manufactured by DIC), and bisphenol A epoxy resin ( Epoxy equivalent 180, "jER828EL" manufactured by Mitsubishi Chemical Corporation) 12 parts, solid content 60 of a phenolic hardener containing a three-dimensional skeleton (hydroxy equivalent of 125, "LA7054" manufactured by DIC (Stock), nitrogen content about 12% by mass) 10 parts of MEK solution of mass% is heated and dissolved in 40 parts of methyl ethyl ketone and 40 parts of cyclohexanone to make a resin varnish, which is applied as a support to a PET film with a release layer (made by LINTEC (stock) PET501010", thickness 38 μm), heated at 100°C for 4 minutes to obtain a peeling layer G of 5 μm. The lowest melt viscosity was measured in the same manner as in Production Example 1-A, and the result was 5,000 poise.

<Production example 1-H: Production of peeling layer H> 10 parts of polyvinyl acetal resin (BX-5Z manufactured by Sekisui Chemical Co., Ltd.) was heated and dissolved in 45 parts of methyl ethyl ketone and 45 parts of cyclohexanone to prepare a resin varnish, which was coated on a PET film (Toray) as a support R60 manufactured by the company, thickness 38 μm), and heated at 100° C. for 4 minutes to obtain a peeling layer H of 5 μm. The lowest melt viscosity was measured by the same method as in Production Example 1-A, and the result was a value exceeding 20,000 poise.

<Production example 1-I: Preparation of peeling layer I> A commercially available polyimide film with a support (Protect film PFEKE 1025P manufactured by Arisawa Manufacturing Co., Ltd.) was used as the release layer I. The lowest melt viscosity was measured by the same method as in Production Example 1-A, and the result was a value exceeding 20,000 poise.

<Production example 2-A1: Production of resin composition layer A1> Make 5 parts of liquid bisphenol A epoxy resin (epoxy equivalent 180, "Epikote 828EL" manufactured by Mitsubishi Chemical Co., Ltd.), and biphenyl epoxy resin (epoxy equivalent 269, manufactured by Nippon Kayaku Co., Ltd.) NC3000") 20 parts, biphenyl type epoxy resin (epoxy equivalent 185, "YX4000" manufactured by Mitsubishi Chemical Co., Ltd.) 10 parts, naphthalene type epoxy resin (epoxy equivalent 283, Nippon Steel & Sumikin Chemical Co., Ltd.) Made "ESN475V") 5 parts, phenoxy resin (Mitsubishi Chemical Co., Ltd. "YL7553BH30", solid content 30% by mass cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution) 15 parts, It is heated and dissolved in 10 parts of MEK and 15 parts of cyclohexanone while stirring. Among them, mixed with three cresol novolac resin (hydroxy equivalent 151, DIC (stock) "LA-3018", nitrogen content about 18% by weight) solid content of 50% by weight of 1-methoxy-2 -6 parts of propanol solution, 25 parts of active ester hardener ("HPC-8000-65T" made by DIC Co., Ltd., 65% by mass non-volatile toluene solution with active base equivalent of about 223), reactive flame retardant ( Hydroxyl equivalent 162, (shares) "HCA-HQ" manufactured by Sanko, with a phosphorus content of 9.5%) 3 parts, spherical silica (average particle size 1.0μm, "SP507-05" manufactured by Nippon Steel & Sumikin Materials, with amino groups) Silane treatment) 170 parts, N,N-dimethyl-4-aminopyridine ((DMAP), manufactured by Tokyo Chemical Industry Co., Ltd.) 1 part of solution adjusted to 5% non-volatile content by MEK, 1-benzyl -2-Phenylimidazole ("1B2PZ" manufactured by Shikoku Kasei Co., Ltd.) was adjusted to 5 parts of a 5% non-volatile solution by MEK, and dispersed uniformly with a high-speed rotating mixer to prepare varnish A1 for the resin composition layer. Coating varnish A1 for the resin composition layer on a PET film with a release layer as a protective film (“PET501010” manufactured by LINTEC Co., Ltd., thickness 38μm), and heating at 100°C for 4 minutes to obtain a resin composition with a thickness of 10μm Layer A1. The lowest melt viscosity was measured in the same manner as in Production Example 1-A, and the result was 4,000 poise.

<Production example 2-A2: Production of resin composition layer A2> Except for changing the thickness from 10 μm to 5 μm, a resin composition layer A2 was obtained in the same manner as in Production Example 1-I. The lowest melt viscosity was measured in the same manner as in Production Example 1-A, and the result was 4,000 poise.

<Production example 2-A3: Production of resin composition layer A3> Except for changing the heating temperature from 100°C to 120°C, a resin composition layer A3 was obtained in the same manner as in Production Example 1-I. The lowest melt viscosity was measured in the same manner as in Production Example 1-A, and the result was 8,000 poise.

<Production example 2-A4: Production of resin composition layer A4> Except for changing the heating temperature from 100°C to 150°C, a resin composition layer A4 was obtained in the same manner as in Production Example 1-I. The lowest melt viscosity was measured in the same manner as in Production Example 1-A, and the result was 20,000 poise.

<Production example 2-B: Production of resin composition layer B> Make 5 parts of liquid bisphenol A epoxy resin (epoxy equivalent 180, "Epikote 828EL" manufactured by Mitsubishi Chemical Co., Ltd.), and biphenyl epoxy resin (epoxy equivalent 269, manufactured by Nippon Kayaku Co., Ltd.) NC3000") 20 parts, biphenyl type epoxy resin (epoxy equivalent 185, "YX4000" manufactured by Mitsubishi Chemical Co., Ltd.) 10 parts, naphthalene type epoxy resin (epoxy equivalent 283, Nippon Steel & Sumikin Chemical Co., Ltd.) Made "ESN475v") 5 parts, phenoxy resin (Mitsubishi Chemical Co., Ltd. "YL7553BH30", 30 mass% solid content of cyclohexanone: methyl ethyl ketone (MEK) 1:1 solution) 15 parts, It is heated and dissolved in 10 parts of MEK and 15 parts of cyclohexanone while stirring. In it, 12 parts of a 60 wt% MEK solution containing three phenol novolac resins (hydroxy equivalent 125, DIC (Stock) "LA-7054", nitrogen content about 12 wt%) containing 60 wt% of solid content, naphthol-based Hardener (Hydroxy equivalent 215, Nippon Steel & Sumitomo Metal Co., Ltd. "SN-485") 60 wt% MEK solution 12 parts, reactive flame retardant (Hydroxy equivalent 162, (Stock) Sanko's "HCA" -HQ", phosphorus content 9.5%) 3 parts, spherical silica (average particle size 1.0μm, "SP507-05" manufactured by Nippon Steel & Sumikin Materials, with aminosilane treatment) 170 parts, N,N-di Methyl-4-aminopyridine ((DMAP), manufactured by Tokyo Chemical Industry Co., Ltd.) is adjusted to a non-volatile content of 5% by MEK, 1 part of 1-benzyl-2-phenylimidazole (Shikoku Kasei ( Stock) made "1B2PZ") 5 parts of a solution adjusted to 5% non-volatile content by MEK, and uniformly dispersed with a high-speed rotating mixer to prepare varnish B for resin composition layer. Coating varnish B for the resin composition layer on a PET film with a release layer as a protective film ("PET501010" manufactured by LINTEC Co., Ltd., thickness 38μm), and heating at 100°C for 4 minutes to obtain a resin composition with a thickness of 10μm Layer B. The lowest melt viscosity was measured in the same manner as in Production Example 1-A, and the result was 4,000 poise.

<Example 1: Production of Resin Sheet A> On the resin composition layer A1 obtained in Production Example 2-A1, the release layer A obtained in Production Example 1-A was bonded to form a resin sheet A. The laminating system is performed by using a batch-type vacuum pressure laminator MVLP-500 (trade name, manufactured by Mingji (Stock)), reducing pressure for 30 seconds to make the air pressure below 13hPa, and then at 120℃, 30 seconds, pressure It is performed by crimping at 0.74 MPa.

<Example 2: Production of Resin Sheet B> A resin sheet B was produced in the same manner as in Example 1, except that the resin composition layer B obtained in Production Example 2-B was used instead of the resin composition layer A1.

<Example 3: Production of Resin Sheet C> A resin sheet C was produced in the same manner as in Example 1, except that the release layer B obtained in Production Example 1-B was used instead of the release layer A.

<Example 4: Production of Resin Sheet D> A resin sheet D was produced in the same manner as in Example 1, except that the release layer C obtained in Production Example 1-C was used instead of the release layer A.

<Example 5: Production of Resin Sheet E> A resin sheet E was produced in the same manner as in Example 1, except that the release layer D obtained in Production Example 1-D was used instead of the release layer A.

<Example 6: Production of Resin Sheet F> A resin sheet F was produced in the same manner as in Example 1, except that the adhesive layer I obtained in Production Example 1-I was used instead of the release layer A.

<Example 7: Production of Resin Sheet G> A resin sheet G was produced in the same manner as in Example 1, except that the release layer E obtained in Production Example 1-E was used instead of the release layer A.

<Example 8: Production of Resin Sheet H> A resin sheet H was produced in the same manner as in Example 1, except that the release layer F obtained in Production Example 1-F was used instead of the release layer A.

<Example 9: Production of Resin Sheet I> A resin sheet I was produced in the same manner as in Example 1, except that the resin composition layer A2 obtained in Production Example 2-A2 was used instead of the resin composition layer A1.

<Example 10: Production of Resin Sheet J> The same as Example 1 except that instead of the release layer A, the release layer G obtained in Production Example 1-G was used, and the resin composition layer A3 obtained in Production Example 2-A3 was used instead of the resin composition layer A1 To make a resin sheet J.

<Example 11: Production of Resin Sheet K> A resin sheet K was produced in the same manner as in Example 1, except that the resin composition layer A4 obtained in Production Example 2-A4 was used instead of the resin composition layer A1.

<Example 12: Production of Resin Sheet L> A resin sheet L was produced in the same manner as in Example 1, except that the release layer H obtained in Production Example 1-H was used instead of the release layer A.

<Example A: Manufacturing of multilayer circuit board> (1) Steps to prepare the substrate On both sides of a glass cloth base epoxy resin copper-clad laminate (the thickness of copper foil is 18μm, the thickness of the substrate is 0.8mm, "R5715ES" manufactured by Matsushita Electric Works Co., Ltd.), the wiring pattern is formed by etching and the surface is produced The inner copper area (the proportion of the area where the circuit layer is formed) is 30% of the inner circuit board. Use a micro-etchant (MEC (stock) "CZ8100") to roughen the copper circuit of the inner circuit board.

(2) Laminating the resin sheet on the substrate The protective film was peeled off from the resin sheets A to L produced in each example, and the inner layer circuit was laminated using a batch-type vacuum pressure laminator MVLP-500 (trade name, manufactured by Mingji Co., Ltd.) To both sides of the inner circuit board produced in the above step (1). The lamination is performed by reducing the pressure for 30 seconds to bring the air pressure to 13 hPa or less, and then pressure-bonding at 120° C. for 30 seconds and a pressure of 0.74 MPa.

(3) Steps to harden the resin composition layer From the inner layer circuit board laminate obtained in the above step (2), for the laminates of the resin sheets A to E and G to K produced in Examples 1 to 5 and 7 to 11, the support was peeled and removed. For Example 6, The laminate of resin sheets F and L produced by and 12, peel off both the release layer and the support, and cure the resin composition layer at 170°C for 30 minutes to form an insulating layer to obtain an inner layer circuit Substrate laminate.

(4) Desmear treatment step The inner layer circuit substrate laminate obtained in the above step (3) was immersed in Swelling Dip Securigand P of ATOTECH Japan Co., Ltd. as a swelling liquid at 60°C for 5 minutes. Next, it was immersed in Concentrate Compact P (KMnO ₄ : 60 g/L, NaOH: 40 g/L aqueous solution) of ATOTECH Japan Co., Ltd. as a roughening liquid at 80°C for 30 minutes. Finally, it was immersed in Reduction Solution Securigand P of ATOTECH Japan Co., Ltd. as a neutralizer at 40°C for 5 minutes. Regarding the laminates of the resin sheets A to E and G to K produced in Examples 1 to 5 and 7 to 11, the release layer was dissolved and removed by this step.

<Test example 1: Peel strength of peeling layer> In the resin sheets F and L of Examples 6 and 12, cut a portion with a width of 10 mm and a length of 100 mm, and grasp one end of it with a clamp (TSE Co., Ltd. Autocom type testing machine AC-50C-SL), and place it in the chamber The load (gf/cm) at the time of tearing 35 mm in the vertical direction at a speed of 50 mm/min was measured under temperature.

<Test Example 2: Evaluation of Circuit Exposure> Cut out a width of 5mm and a length of 5mm from the substrate after the step (4) of the above-mentioned embodiment A step (4) of the desmear treatment step, and use a field emission scanning electron microscope (SU8200Series manufactured by Hitachi High-Technologies) for energy dispersive X-ray analysis The device performs elemental analysis to evaluate the exposure of the circuit. If the detection rate of Cu is 80 atomic% or more, it is regarded as "○", and if it is less than 80 atomic %, it is regarded as "×".

<Test Example 3: Confirmation of the residue of the peeling layer> Cut out a width of 10mm and a length of 10mm from the substrate after the desmear treatment step of step (4) of the above-mentioned embodiment A, and after grinding the cross section, observe it with a field emission scanning electron microscope (SU8200Series manufactured by Hitachi High-Technologies). The residue of the peeling layer was evaluated. If the residue of the peeling layer was less than 1 μm, it was regarded as "○", if it was 1 μm or more and less than 3 μm, it was regarded as "△", and if it was 3 μm or more, it was regarded as "×".

<Test Example 4: Evaluation of Implantability> Cut out a width of 10mm and a length of 10mm from the de-smear-treated substrate, and observe the surface condition with a microscope (Keyence Microscope VH-5500) to evaluate the embedment. If the void is 0, it is regarded as "○". If there is more than one place and less than three places, it is regarded as "△", and if there are more than 4 places, it is regarded as "×".

The following Table 1 shows the measurement results and evaluation results of the resin sheets and multilayer wiring boards of each example.

As a result of the above results, the circuit board obtained by the manufacturing method of the multilayer circuit board of the present invention has circuit exposure with a Cu detection rate of 80 at% or more, so it is judged that even if the conductive wires are soldered, there is no problem of poor conduction.

10: Circuit board 11: circuit layer 12: substrate 20: resin sheet 21: Support 22: peeling layer 23: Resin composition layer 100 multilayer circuit board 100’: Multilayer circuit board 111: circuit layer 112: substrate 121: Support 122: peeling layer 123: resin composition layer

[FIG. 1] A cross-sectional view schematically showing a circuit board in an embodiment. [Fig. 2] A cross-sectional view schematically showing a resin sheet in one embodiment. Fig. 3 is a cross-sectional view schematically showing a laminated circuit board obtained by laminating resin sheets on a circuit board in an embodiment. Fig. 4 is a cross-sectional view schematically showing the laminated circuit board after removing the support and the peeling layer in one embodiment.

100’: Multilayer circuit board

111: circuit layer

112: substrate

123: resin composition layer

Claims (17)

A manufacturing method of a multilayer circuit board, which comprises: (1) A step of preparing a resin sheet having a release layer and a resin composition layer provided on one surface of the release layer, (2) The step of preparing a circuit board having a substrate and a circuit layer formed on a part of the surface of the substrate, (3) The step of laminating the resin sheet on the circuit board so that the circuit layer penetrates the resin composition layer and reaches the release layer, and (4) The step of removing the peeling layer to expose a part of the circuit layer. The method for manufacturing a multilayer circuit board according to claim 1, wherein the resin composition layer includes a thermosetting resin. The method for manufacturing a multilayer circuit board according to claim 2, wherein the resin composition layer includes (A) epoxy resin and (B) hardener. The method for manufacturing a multilayer circuit board according to claim 1, wherein the release layer comprises a cellulose resin, a polyvinyl acetal resin, a poly(meth)acrylate resin, a polyester resin, a polybutadiene resin, and a polyamide resin. One or more resins in the group of imine resin and epoxy resin. The method for manufacturing a laminated circuit board according to claim 1, wherein the minimum melt viscosity of the peeling layer is higher than the minimum melt viscosity of the resin composition layer. The method for manufacturing a multilayer circuit board of claim 1, wherein the minimum melt viscosity of the peeling layer is 10,000 poise or more. The method for manufacturing a multilayer circuit board according to claim 1, wherein the minimum melt viscosity of the resin composition layer is 5,000 poise or less. The method for manufacturing a multilayer circuit board of claim 1, wherein after step (3) and before step (4), or after step (4), further comprising (5) hardening the above-mentioned resin composition layer into a hardened body layer step. The method for manufacturing a laminated circuit board according to claim 1, wherein the method for removing the peeling layer in step (4) is peeling removal. The method for manufacturing a laminated circuit board according to claim 9, wherein the peeling strength of the peeling layer when the peeling layer is removed in step (4) is 200 gf/cm or less. The method for manufacturing a laminated circuit board according to claim 1, wherein the method for removing the peeling layer in step (4) is dissolution removal. The method of manufacturing a laminated circuit board according to claim 11, wherein the thickness of the peeling layer before the lamination is 25 μm or less. The method for manufacturing a laminated circuit board according to claim 1, wherein the resin sheet further has a support provided on the surface of the release layer opposite to the resin composition layer, After step (3) and before step (4), it further includes (6) the step of removing the support body, or in step (4), the support body is removed together with the peeling layer to make a part of the circuit layer Exposed. The method for manufacturing a laminated circuit board according to claim 1, wherein the thickness of the peeling layer before lamination is smaller than the thickness of the resin composition layer before lamination. The method of manufacturing a laminated circuit board of claim 1, wherein the thickness of the peeling layer before lamination is A (μm), the thickness of the resin composition layer before lamination is B (μm), and the circuit The height of the layer is regarded as C (μm), and when the area ratio of the circuit layer is regarded as D (%) relative to the substrate surface in the range where the resin sheet is laminated in step (3), it becomes (A+B )/{C×(1-0.01×D)}>1. A resin sheet, which is a resin sheet having a release layer and a resin composition layer provided on one surface of the release layer, and is used in a manufacturing method of a build-up circuit board including the following steps: (1) The step of preparing the resin sheet, (2) the step of preparing a circuit board having a substrate and a circuit layer formed on a part of the surface of the substrate, and (3) the circuit layer penetrates the resin composition layer to reach The method of the peeling layer includes the step of laminating the resin sheet on the circuit board, and (4) the step of removing the peeling layer to expose a part of the circuit layer. A resin sheet having a release layer and a resin composition layer provided on one surface of the release layer, The above-mentioned release layer comprises a group selected from the group consisting of cellulose resin, polyvinyl acetal resin, poly(meth)acrylate resin, polyester resin, polybutadiene resin, polyimide resin and epoxy resin 1 or more resins, The resin composition layer includes (A) epoxy resin and (B) hardener, The minimum melt viscosity of the release layer is higher than the minimum melt viscosity of the resin composition layer.

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