JP2008182146A - Multi-layer circuit board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-layer circuit board with a smooth front surface, which can carry out fine wiring pattern forming and has an electrical insulation layer excellent in a fire retardant nature, and to provide a method of manufacturing the multi-layer circuit board. <P>SOLUTION: The method includes steps of: laminating a thermosetting resin composition containing an electric insulation polymer, curing agent and filler on a front surface of an inner layer substrate having a conductor layer; subsequently forming an electrical insulation layer (B1) by curing; laminating the thermosetting resin composition which contains the electric insulation polymer and the curing agent but doesn't contain any filler on a front surface thereof; subsequently contacting a metal with a compound having a coordination structure; forming an electrical insulation layer (B2) by curing; and setting the thickness of the electrical insulation layer (B2) to 1/5 to 1/50 of the thickness of the electrical insulation layer (B1). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multilayer circuit board and a manufacturing method thereof, and more particularly to a multilayer circuit board having a smooth surface and capable of forming a fine wiring pattern and having an electrically insulating layer excellent in flame retardancy, and a manufacturing method thereof. .

As electronic devices become smaller and more multifunctional, circuit boards used in electronic devices are also required to have higher density and higher performance.
In order to increase the density of a circuit board, the circuit board is generally multilayered. A multilayer circuit board is usually obtained by laminating an electric insulating layer on an inner layer substrate having a conductor layer formed on the surface, and further forming a conductor layer on the electric insulating layer. The electrical insulating layer and the conductor layer can be laminated in several layers as required.
The conductor layers in the multilayer circuit board are usually insulated by an electrical insulating layer, but are connected by wiring such as via holes in order to energize the conductor layers as necessary.
In a multilayer circuit board, in order to ensure insulation performance, the interface between the conductor layer formed on the surface of the inner layer board and the electrical insulation layer laminated thereon, and the electrical insulation layer and the conductor layer formed outside thereof High adhesion between layers such as an interface is particularly required. If the adhesion between these layers is insufficient, a gap may be formed between the conductor layer and the electrical insulation layer, and water vapor, water, etc. may enter there and the electrical insulation may be lowered. Also, the via hole may be overloaded and disconnection may occur.

  In order to solve this problem, an uncured or semi-cured resin layer is formed using a curable resin composition containing a carboxyl group-containing polymer and a curing agent on an inner layer substrate having a conductor layer formed on the surface. Then, a compound having a structure capable of coordinating with the metal is brought into contact with the surface of the resin layer, and then the resin layer is cured to form an electrical insulating layer, and a metal thin film layer is formed on the surface of the electrical insulating layer. A method for manufacturing a multilayer circuit board has been proposed in which a conductor layer including the metal thin film layer is formed thereafter (Patent Document 1).

On the other hand, in general, a multilayer circuit board having a high-density wiring pattern has a problem that the conductor layer and the board generate heat during use. Therefore, improvement of the flame retardance of the electrical insulation layer is required as a safety measure. In general, a flame retardant is blended for improving the flame retardancy of the electrical insulating layer. However, it is recommended to use a non-halogen flame retardant as a flame retardant in consideration of the environment.
For example, Patent Document 2 discloses a multilayer circuit board in which a metal hydroxide coated with a specific acidic compound is blended in an electrical insulating film (electrical insulating layer) as a flame retardant. However, the surface of the electrical insulating film blended with such a flame retardant has irregularities reflecting the distribution of the flame retardant, and is unsuitable for forming a fine wiring pattern.

JP 2003-158373 A JP 2005-264076 A

  More specifically, the present invention provides a multilayer circuit board having a smooth surface and capable of forming a fine wiring pattern and having an electrically insulating layer excellent in flame retardancy, and a method for producing the same. Objective.

  In order to achieve the above object, the present inventors have laminated a surface of an insulating layer containing a flame retardant having excellent flame retardancy by laminating a thermosetting resin composition not containing a flame retardant. Was studied, and the production method disclosed in Patent Document 1 was studied. As a result of further intensive studies, when a thermosetting resin composition having a specific thickness is used, a fine wiring pattern can be formed with a smooth surface, excellent flame retardancy, and different electrically insulating layers. As a result, the present inventors have found that the adhesiveness of the film is improved, and have completed the present invention based on these findings.

Thus, according to the first aspect of the present invention, the first conductor layer (A1), the first electrical insulation layer (B1), the second electrical insulation layer (B2), and the second conductor layer are formed on the surface of the inner layer substrate. (A2) is a multilayer circuit board formed by stacking in this order,
The electrical insulation layer (B1) is an insulation layer obtained by curing a thermosetting resin composition (b1) containing an electrical insulation polymer 1, a curing agent 1, and a filler,
The electrical insulating layer (B2) is substantially free of filler and has a structure capable of coordinating the thermosetting resin composition (b2) containing the electrical insulating polymer 2 and the curing agent 2 to the metal. And is cured after contacting with a compound having
A multilayer circuit board is provided in which the thickness of the electrical insulation layer (B2) is 1/5 to 1/50 of the thickness of the electrical insulation layer (B1).

The electrically insulating polymer 2 preferably has a carboxyl group or an acid anhydride group, and the curing agent 2 is preferably a polyvalent epoxy compound.
The thermosetting resin composition (b2) preferably further contains a carboxylic acid anhydride having two or more acid anhydride groups in the molecule.
It is preferable that the filler is a flame retardant.

According to the second aspect of the present invention, a first conductor layer (A1), a first electrical insulation layer (B1), a second electrical insulation layer (B2), and a second conductor layer ( A method of manufacturing a multilayer circuit board in which A2) is laminated in this order, and includes the following steps (1) to (8) is provided.
(1) The thermosetting resin composition (b1) containing the electrically insulating polymer 1, the curing agent 1, and the filler is uncured or semi-cured on the surface of the inner layer substrate having the first conductor layer (A1). Laminating in the state of;
(2) A step of forming the first electrical insulating layer (B1) by curing the thermosetting resin composition (b1);
(3) A thermosetting resin composition (b2) containing substantially no filler and containing the electrically insulating polymer 2 and the curing agent 2 on the surface of the first electrically insulating layer (B1). Laminating in an uncured or semi-cured state and at a thickness of 1/5 to 1/50 of the thickness of the electrical insulating layer (B1);
(4) A step of bringing the surface of the thermosetting resin composition (b2) into contact with a compound having a structure capable of coordinating with a metal;
(5) Next, the step of forming the second electrically insulating layer (B2) by curing the thermosetting resin composition (b2);
(6) forming a metal thin film layer on the surface of the second electrical insulating layer (B2);
(7) A step of forming a second conductor layer (A2) including the metal thin film layer.

The electrically insulating polymer 2 preferably has a carboxyl group or an acid anhydride group, and the curing agent 2 is preferably a polyvalent epoxy compound.
The thermosetting resin composition (b2) preferably further contains a carboxylic acid anhydride having two or more acid anhydride groups in the molecule.
The filler is preferably a flame retardant.

  According to the present invention, a multilayer circuit board, more specifically, a multilayer circuit board having a smooth surface, capable of forming a fine wiring pattern and having an electrically insulating layer excellent in flame retardancy, and a method for manufacturing the same are provided. Is done. The multilayer circuit board provided by the present invention can be suitably used as a semiconductor element such as a CPU or a memory or other mounting component board in an electronic device such as a computer or a mobile phone.

The multilayer substrate of the present invention has a first conductor layer (A1), a first electrical insulation layer (B1), a second electrical insulation layer (B2), and a second conductor layer (A2) on the surface of the inner layer substrate. Is a multilayer circuit board laminated in this order,
The electrical insulation layer (B1) is an insulation layer obtained by curing a thermosetting resin composition (b1) containing an electrical insulation polymer 1, a curing agent 1, and a filler,
The electrical insulating layer (B2) is substantially free of filler and has a structure capable of coordinating the thermosetting resin composition (b2) containing the electrical insulating polymer 2 and the curing agent 2 to the metal. And is cured after contacting with a compound having
The multilayer circuit board is characterized in that the thickness of the electrical insulation layer (B2) is 1/5 to 1/50 of the thickness of the electrical insulation layer (B1).

(Inner layer substrate)
The inner layer substrate used in the present invention is a substrate in which the conductor layer (A1) is formed on the surface of the electrical insulating layer (B0). Examples of the inner layer substrate include a printed wiring board and a silicon wafer substrate. The thickness of the inner layer substrate is preferably 50 μm to 2 mm, more preferably 60 μm to 1.6 mm, and particularly preferably 100 μm to 1 mm.

The electrical insulation layer (B0) constituting the inner layer substrate is mainly composed of the electrical insulation polymer 0 having electrical insulation. The electrically insulating polymer 0 is not particularly limited, and examples thereof include alicyclic olefin polymers, epoxy resins, maleimide resins, acrylic resins, methacrylic resins, diallyl phthalate resins, triazine resins, aromatic polyether polymers, cyanate ester heavy polymers. Examples include coalescence and polyimide. Usually, a curable resin composition containing these electrically insulating polymer 0 and curing agent 0 is cured to obtain an electrically insulating layer (B0). Further, the inner layer substrate may contain glass fibers, resin fibers, etc. for strength improvement. The material of the conductor layer (A1) constituting the inner layer substrate is usually a conductive metal. The thickness of the conductor layer (A1) is preferably 0.1 μm to 50 μm, more preferably 0.5 μm to 20 μm, and particularly preferably 1 μm to 10 μm. The conductor layer (A1) may be formed on both surfaces of the inner layer substrate, may form a circuit, and may be connected to each other through a via hole or the like.
In the present invention, electrical insulation means that the volume resistivity according to ASTM D257 is 1 × 10 ¹² Ω · cm or more.

(Electrical insulation layer (B1))
The first electrical insulating layer (B1) laminated on the surface of the inner layer substrate is an uncured or semi-cured thermosetting resin composition (b1) containing the electrically insulating polymer 1, the curing agent 1, and the filler. It is formed by laminating in a cured state and then curing.
Here, the uncured state is a state in which the electrically insulating polymer 1 remains soluble and soluble after lamination in a solvent that was soluble before lamination. The semi-cured state is a state where it is cured only to such an extent that it can be further cured by heating. As a semi-cured state, the volume swelling rate when immersed in the solvent for 24 hours is preferably 200% or more before immersion.
The thickness of the electrical insulating layer (B1) is preferably 0.1 to 150 μm, more preferably 0.5 to 100 μm, and particularly preferably 1 to 80 μm.

(Thermosetting resin composition (b1))
The electrically insulating polymer 1 may be anything as long as it has electrical insulating properties. For example, epoxy resin, maleimide resin, acrylic resin, methacrylic resin, diallyl phthalate resin, triazine resin, polyether ketone resin, alicyclic olefin polymer , Aromatic polyether polymer, benzocyclobutene polymer, cyanate ester polymer, polyimide and the like.
Although there is no special restriction | limiting in the weight average molecular weight of the electrically insulating polymer 1, Usually, 10,000-1,000,000, Preferably it is 50,000-500,000. When the weight average molecular weight is within this range, the compatibility with the other components of the thermosetting resin composition (b1) is good, and the strength of the cured electrical insulating layer (B1) is also good. In the present invention, the weight average molecular weight Mw is a polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).
The curing agent 1 used in the present invention is not particularly limited as long as it cures the electrically insulating polymer 1 and is appropriately selected depending on the type of the electrically insulating polymer 1. For example, an ionic curing agent, a radical curing agent, or a curing agent having both ionic and radical properties is used.

(Filler)
The filler contained in the thermosetting resin composition (b1) is preferably a flame retardant. As the flame retardant, a halogen-free compound that does not generate a halogen-containing harmful substance during incineration (hereinafter sometimes referred to as a non-halogen flame retardant) is more preferable from the viewpoint of environmental protection. Non-halogen flame retardants include, for example, metal hydroxides such as aluminum hydroxide and magnesium hydroxide; ammonium orthophosphate, orthophosphoric acid, condensed phosphoric acid, anhydrous phosphoric acid, urea phosphate, phosphoric acid serving as a phosphoric acid source Ammonium monohydrogen and a mixture thereof, and melamine, dicyancyanamide, guanidine, guanylurea and a mixture thereof as nitrogen sources, urea as a condensing agent, urea phosphate (which also serves as a phosphate source) and In the presence of these mixtures, a phosphate of a basic nitrogen-containing compound obtained by subjecting it to a heat condensation reaction and then calcining; As the phosphate of the basic nitrogen-containing compound, preferred compounds are melamine polyphosphate compounds such as melamine polyphosphate, melam salt of polyphosphate, melem salt of polyphosphate, melamine / melam / melem double salt of polyphosphate.

  Other flame retardants include antimony compounds such as antimony trioxide, antimony pentoxide, and sodium antimonate; inorganic flame retardants such as zinc borate, guanidine sulfamate, zirconium compounds, molybdenum compounds, tin compounds; triphenyl phosphate, triphenyl Cresyl phosphate, trixylenyl phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, resorcinol bis (diphenyl) phosphate, 2 -Ethylhexyl diphenyl phosphate, dimethyl methyl phosphate, triallyl phosphate, diethylbi (Hydroxyethyl) aminomethyl phosphate, triallyl phosphate, tris (3-hydroxypropyl) phosphine oxide, glycidyl-α-methyl-β-di (butoxy) phosphinyl propionate, dibutylhydroxymethylphosphonate, dimethylmethyl phosphate Nate, aromatic condensed phosphate ester, di (ethoxy-bis- (2-hydroxyethyl) -aminomethyl phosphate, di (polyoxyethylene) -hydroxymethyl phosphate, ammonium polyphosphate, butyl pyrophosphate, butyl acid phosphate , Butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, diethylphenyl phosphonate, dimethylphenyl phosphonate, di (isopropyl) N, N- Scan (2-hydroxyethyl) aminomethyl phosphonate, dibutylbis (2-hydroxypropyl) pyro phosphonate, and the like phenyl phosphinic acid.

  Fillers other than flame retardants include carbonates such as calcium carbonate, magnesium carbonate, and barium carbonate; silicates such as magnesium silicate, calcium silicate, zirconium silicate, talc, and clay; zinc oxide, titanium oxide, Examples thereof include oxides such as magnesium oxide, alumina, and silica; sulfates such as barium sulfate and calcium sulfate; and crosslinked fine particles of polymer compounds such as epoxy, rubber, urethane, polyimide, and polyamide.

A filler can be used individually or in combination of 2 or more types. The content of the filler is preferably 1 to 90% by weight, more preferably 5 to 75% by weight, and particularly preferably 10 to 50% by weight with respect to the thermosetting resin composition (b1). When the amount of the filler used is within this range, the adhesion of the electrical insulating layer (B1) to the conductor layer (A1) is good, and when the filler is a flame retardant, the flame retardancy is also good.
The shape and size of the filler are not limited. When the filler is particulate, the volume average particle diameter of the primary particles is preferably 0.1 to 5.0 μm, and more preferably 0.5 to 2.0 μm. When the particle size is within this range, the laminate property to the inner layer substrate is good.

(Laminated)
There is no particular limitation on the method of laminating the thermosetting resin composition (b1) on the surface of the inner layer substrate in an uncured or semi-cured state, but the thermosetting resin composition (b1) can be removed from a resin film or metal foil. Examples of the method include a method in which a film-like or sheet-like molded body formed by spreading (casting) on a support to be formed is dried and bonded to the conductor layer (A1) of the inner layer substrate and bonded under heat.

  As a method for pressure-bonding a film-shaped or sheet-shaped molded product on a substrate, usually, using a pressure laminator, a press, a vacuum laminator, a vacuum press, a roll laminator or the like, Crimping is performed so that no substantial void exists at the interface. The surface shape of the laminated thermosetting resin composition (b1) is preferably such that the step due to the conductor layer (A1) is eliminated. The thermocompression bonding is preferably performed under a reduced pressure of 100 kPa to 1 Pa in order to improve the embedding property in the wiring and suppress the generation of bubbles and the like. The temperature during crimping is preferably 30 to 250 ° C., more preferably 70 to 200 ° C., the pressure is preferably 10 kPa to 20 MPa, more preferably 100 kPa to 10 MPa, and the time is preferably 30 seconds to 5 hours, more preferably. Is 1 minute to 3 hours.

(Curing)
The operation of forming the first electrical insulating layer (B1) by curing the laminated thermosetting resin composition (b1) on the surface of the inner layer substrate is usually performed by laminating the thermosetting resin composition. The entire inner layer substrate is heated. The curing conditions are appropriately selected according to the type of the curing agent, but the temperature is preferably 30 to 400 ° C, more preferably 70 to 300 ° C, particularly preferably 100 to 200 ° C, and the time is preferably 0.1 to 5 hours, more preferably 0.5 to 3 hours. The heating method is not particularly limited, and for example, a hot air drying furnace is used.

(Electrical insulation layer (B2))
The second electrically insulating layer (B2) does not substantially contain a filler, and the thermosetting resin composition (b2) containing the electrically insulating polymer 2 and the curing agent 2 is uncured or semi-cured. Laminated on the surface of the first electrical insulating layer (B1) in a state, the surface of the thermosetting resin composition (b2) is brought into contact with a compound having a structure capable of coordinating with a metal, and then cured. Is formed.
The thickness of the electrical insulation layer (B2) is 1/5 to 1/50 of the thickness of the electrical insulation layer (B1), preferably 1/8 to 1/40, more preferably 1/10 to 1. / 20. When the thickness is within this range, the surface is smooth and a fine wiring pattern can be formed, and the flame retardancy is not adversely affected.

(Thermosetting resin composition (b2))
The thermosetting resin composition (b2) substantially does not contain a filler, but contains an electrically insulating polymer 2 and a curing agent 2. Here, “substantially not containing” means not containing 5 mass% or more in the thermosetting resin composition (b2).
The electrically insulating polymer 2 is not limited as long as it has electrical insulating properties, but has a carboxyl group or an acid anhydride group (hereinafter, both may be collectively referred to as “carboxyl group or the like”). Electrical insulating polymers are preferred. The content of carboxyl groups and the like is preferably in the range of 0.25 to 2.5 mmol / g, more preferably in the range of 0.50 to 2.0 mmol / g, as a molar equivalent per 1 g of the electrically insulating polymer. If the content of carboxyl groups, etc. is too small, the plating adhesion and heat resistance of the electrical insulation layer may be reduced. If the content of carboxyl groups, etc. is too large, the insulation properties of the electrical insulation layer may be reduced. There is.

  The weight average molecular weight (Mw) of the electrically insulating polymer 2 is preferably 15,000 to 150,000, and more preferably 20,000 to 100,000. If Mw is too small, there is a risk that the strength when the obtained molded product is a cured product will be insufficient, or that the electrical insulation will be reduced. On the other hand, if the Mw is too large, the compatibility with the curing agent 2 decreases, and the surface roughness when the resulting molded product is a cured product is increased. Therefore, when the cured product is used as a laminate, There is a possibility that the accuracy of the wiring pattern formed on the surface is lowered.

The electrically insulating polymer having a carboxyl group or the like has a carboxyl group or the like directly on the main chain of the electrically insulating polymer constituting the skeleton, or other two groups such as a methylene group, an oxy group, an oxycarbonyloxyalkylene group, and a phenylene group. It is bonded through a valent linking group.
The polymer that forms the skeleton of the electrically insulating polymer having a carboxyl group or the like is not particularly limited, and specific examples thereof include maleimide resin, acrylic resin, diallyl phthalate resin, triazine resin, alicyclic olefin polymer, aromatic Group polyether polymer, benzocyclobutene polymer, cyanate ester polymer, and polyimide resin; one type may be used alone, or two or more types may be used in combination. Of these, alicyclic olefin polymers, aromatic polyether polymers, benzocyclobutene polymers, cyanate ester polymers and polyimide resins are preferred because of their excellent electrical properties such as dielectric constant and dielectric loss tangent. Cyclic olefin polymers and aromatic polyether polymers are more preferred, and alicyclic olefin polymers are particularly preferred.

In the present invention, the alicyclic olefin polymer is a homopolymer or copolymer of an alicyclic compound (referred to as alicyclic olefin) having a carbon-carbon unsaturated bond, and derivatives thereof (hydrogenated products, etc.). It is a general term. The polymerization mode may be addition polymerization or ring-opening polymerization.
Specific examples of the alicyclic olefin polymer include a ring-opening polymer of a monomer having a norbornene ring (hereinafter referred to as a norbornene monomer) and a hydrogenated product thereof, an addition polymer of a norbornene monomer, Examples include addition polymers of norbornene monomers and vinyl compounds, monocyclic cycloalkene addition polymers, alicyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and hydrogenated products thereof. An example is a polymer in which an alicyclic structure is formed by hydrogenation after polymerization, such as an aromatic olefin hydrogenated product of an aromatic olefin polymer, and has a structure equivalent to an alicyclic olefin polymer. It is. Among these, ring-opening polymers of norbornene monomers and hydrogenated products thereof, addition polymers of norbornene monomers, addition polymers of norbornene monomers and vinyl compounds, and aromatic olefin polymers Aromatic hydrogenated products are preferred, and in particular, hydrogenated products of ring-opening polymers of norbornene monomers are preferred.

  The method for setting the content of the carboxyl group or the like of the electrically insulating polymer within the above range is not limited. For example, (i) a method in which a monomer having a carboxyl group or the like is homopolymerized or copolymerized with a monomer copolymerizable therewith; (ii) a polymer having no carboxyl group or the like A method of introducing a carboxyl group or the like by graft-bonding a compound having a group or the like and a carbon-carbon unsaturated bond, for example, in the presence of a radical initiator; (iii) a precursor of a carboxyl group such as a carboxylate group There is a method of polymerizing a monomer having a group to form a body and then converting a precursor group into a carboxyl group by hydrolysis or the like.

As the carboxyl group-containing alicyclic olefin monomer used in the method (i), 8-hydroxycarbonyltetracyclo [4.4.0.1 ^2,5 . ^{17, 10} ] dodec-3-ene, 5-hydroxycarbonylbicyclo [2.2.1] hept-2-ene, 5-methyl-5-hydroxycarbonylbicyclo [2.2.1] hept-2-ene , 5-carboxymethyl-5-hydroxycarbonylbicyclo [2.2.1] hept-2-ene, 8-methyl-8-hydroxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-carboxymethyl-8-hydroxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 5-exo-6-endo-dihydroxycarbonylbicyclo [2.2.1] hept-2-ene, and 8-exo-9-endo-dihydroxycarbonyltetracyclo [4]. .4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene;

Examples of the acid anhydride group-containing alicyclic olefin monomer used in the method (i) include bicyclo [2.2.1] hept-2-ene-5,6-dicarboxylic acid anhydride, tetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] dodec- ³ -ene-8,9-dicarboxylic anhydride, and hexacyclo [6.6.1.1 ^3,6 . 1 ^10,13 . 0 ^2,7 . 0 ^9,14] heptadec-4-ene-11,12-dicarboxylic acid anhydride; and the like.
The monomer copolymerizable with the carboxyl group-containing alicyclic olefin monomer used in the method (i) is not particularly limited, but an alicyclic olefin monomer having no carboxyl group or the like is preferable. .

Specific examples of the alicyclic olefin monomer having no carboxyl group and the like include bicyclo [2.2.1] hept-2-ene (common name: norbornene), 5-ethyl-bicyclo [2.2. 1] hept-2-ene, 5-butyl-bicyclo [2.2.1] hept-2-ene, 5-ethylidene-bicyclo [2.2.1] hept-2-ene, 5-methylidene-bicyclo [ 2.2.1] Hept-2-ene, 5-vinyl-bicyclo [2.2.1] hept-2-ene, tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene (common name: dicyclopentadiene), tetracyclo ^{[8.4.0.1 11,14.} 0 ^2,8 ] tetradeca-3,5,7,12,11-tetraene, tetracyclo [4.4.0. ^{12, 5} . 1 ^7,10 ] dec-3-ene (common name: tetracyclododecene), 8-methyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methylidene-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-ethylidene-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-vinyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-propenyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13] pentadeca-3,10-diene, pentacyclo [7.4.0.1 ^3,6. 1 ^10,13 . 0 ^2,7 ] pentadeca-4,11-diene, cyclopentene, cyclopentadiene, 1,4-methano-1,4,4a, 5,10,10a-hexahydroanthracene, and 8-phenyl-tetracyclo [4.4. .0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene;

The alicyclic olefin polymer having no carboxyl group or the like used in the method (ii) is obtained by polymerizing the alicyclic olefin monomer having no carboxyl group or the like. The mode of polymerization may be addition polymerization, ring-opening polymerization, or a derivative thereof (hydrogenated product or the like).
Examples of the carbon-carbon unsaturated bond-containing compound having a carboxyl group or the like used in the method (ii) include acrylic acid, methacrylic acid, α-ethylacrylic acid, 2-hydroxyethyl (meth) acrylic acid, maleic acid. Acids, fumaric acid, itaconic acid, endocis-bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid, and methyl-endocis-bicyclo [2.2.1] hept-5-ene- Unsaturated carboxylic acid compounds such as 2,3-dicarboxylic acid; unsaturated carboxylic acid anhydrides such as maleic anhydride, chloromaleic anhydride, butenyl succinic anhydride, tetrahydrophthalic anhydride, and citraconic anhydride; .

As the norbornene-based monomer having a carboxyl group precursor used in the method (iii), 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . ^{17, 10} ] dodec-3-ene, 5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, and 5-methyl-5-methoxycarbonyl-bicyclo [2.2.1] hept- 2-ene; and the like.

  The polymer having a carboxyl group or the like may have a functional group other than the carboxyl group or the like. Examples of the functional group other than the carboxyl group include an alkoxycarbonyl group, a cyano group, a hydroxyl group, an epoxy group, an alkoxyl group, an amino group, an amide group, and an imide group.

(Polyvalent epoxy compound)
The curing agent 2 only needs to cure the electrical insulating polymer 2, but when the electrical insulating polymer 2 is an electrical insulating polymer having a carboxyl group or the like, a polyvalent epoxy compound is preferable. .
The polyvalent epoxy compound is a compound having two or more epoxy groups in the molecule. Examples of polyvalent epoxy compounds include phenol novolac epoxy compounds, cresol novolac epoxy compounds, cresol epoxy compounds, bisphenol A epoxy compounds, bisphenol F epoxy compounds, brominated bisphenol A epoxy compounds, brominated bisphenol F Examples thereof include glycidyl ether type epoxy compounds such as type epoxy compounds and hydrogenated bisphenol A type epoxy compounds, alicyclic epoxy compounds, glycidyl ester type epoxy compounds, glycidyl amine type epoxy compounds, and isocyanurate type epoxy compounds.
These can be used alone or in combination of two or more.

(Carboxylic anhydride having two or more acid anhydride groups in the molecule)
When the electrically insulating polymer 2 is an electrically insulating polymer having a carboxyl group or the like, the thermosetting resin composition (b2) further includes a carboxylic acid having two or more acid anhydride groups in the molecule. It is preferable to contain an anhydride (hereinafter, sometimes referred to as “tetracarboxylic dianhydride”). Examples of tetracarboxylic dianhydrides include pyromellitic anhydride, hexahydropyromellitic anhydride, cyclobutanetetracarboxylic anhydride, naphthalenetetracarboxylic anhydride, benzophenonetetracarboxylic anhydride, undecahydrobenzophenonetetracarboxylic anhydride , Tetralin-dianhydride, ethylene glycol bis (anhydro trimellitate), ethylene glycol bis (anhydro trimellitate) monoacetate, glycerin bis (anhydro trimellitate) monoacetate, 4- (2, 5-Dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, 5- (2,5 dioxotetrahydroxyfuryl) -3-methyl-3- Cyclohexene-1,2-dicarboxylic acid Anhydride, 1,2,3,4-butane tetracarboxylic acid dianhydride, 4,4'-sulfonyldibenzoic phthalic anhydride; and the like. Among these, ethylene glycol bis (anhydro trimellitate), ethylene glycol bis (anhydro trimellitate) monoacetate and glycerin from the viewpoint of compatibility with the other components of the curable resin composition (b2). Bis (anhydrotrimellitate) monoacetate is preferred, and ethylene glycol bis (anhydrotrimellitate) monoacetate and glycerin bis (anhydrotrimellitate) monoacetate are particularly preferred.

The use amount of tetracarboxylic dianhydride and the like is preferably 95: 5 to 65:35 as the respective carboxyl group equivalent ratio of the electrically insulating polymer having a carboxyl group or the like and the carboxylic anhydride, and 90:10 70:30 is more preferable. When the carboxyl group equivalent ratio is within this range, the adhesion to the electrical insulating layer and the conductor layer is good.
The ratio of the epoxy group equivalent of the polyvalent epoxy compound to the total carboxyl group equivalent of the electrically insulating polymer having a carboxyl group and the carboxylic acid anhydride is preferably 0.8 to 1.2, more preferably 0.9. -1.1. Within this range, the electrical insulation and the adhesion between the electrical insulation layer and the conductor layer are good.

  In addition to the above, the curable resin compositions (b1) and (b2) in the present invention include a curing accelerator (eg, tertiary amine compound), a laser processability improver, a heat stabilizer, and weather resistance as necessary. Stabilizers, anti-aging agents, leveling agents, antistatic agents, slip agents, anti-blocking agents, anti-fogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, emulsions, fillers, etc. can be included. . The blending amounts thereof are appropriately selected within a range that does not impair the object of the present invention.

(Laminated)
The thermosetting resin composition (b2) is uncured or semi-cured on the surface of the electrical insulating layer (B1) by the same method as the thermosetting resin composition (b1) described above, and the electric The insulating layer (B1) is laminated at a thickness of 1/5 to 1/50.

(Coordination structure-containing compound)
The compound having a structure capable of coordinating to the metal to be brought into contact with the surface of the thermosetting resin composition (b2) (hereinafter sometimes referred to as “coordination structure-containing compound”) has a structure capable of coordinating to the metal. As long as it has an unshared electron pair such as a compound having a functional group capable of coordinating to a metal such as an amino group, a thiol group, a carboxyl group, or a cyano group, or a heterocyclic compound capable of coordinating with a metal. Examples are compounds. Among these, a heterocyclic compound containing a nitrogen atom, oxygen atom or sulfur atom is particularly preferred, and a heterocyclic compound containing a nitrogen atom is particularly preferred. Such a heterocyclic compound may further have a functional group capable of coordinating to a metal.

  Examples of the heterocyclic compound containing a nitrogen atom, oxygen atom or sulfur atom include pyrroles, pyrrolines, pyrrolidines, pyrazoles, pyrazolines, pyrazolidines, imidazoles, imidazolines, triazoles, tetrazoles, pyridines, Piperidines, pyridazines, pyrimidines, pyrazines, piperazines, triazines, tetrazines, indoles, isoindoles, indazoles, purines, norharmans, perimidines, quinolines, isoquinolines, sinolines, quinosalines Quinazolines, naphthyridines, pteridines, carbazoles, acridines, phenazines, phenanthridine, phenanthrolines, furans, dioxolanes, pyrans, dioxanes, benzofurans, isobenzofurans , Coumarins, dibenzofurans, flavones, trithianes, thiophenes, benzothiophenes, isobenzothiophenes, dithiines, thianthrenes, thienothiophenes, oxazoles, isoxazoles, oxadiazoles, oxazines Morpholines, thiazoles, isothiazoles, thiadiazoles, thiazines, phenothiazines and the like.

  Among these coordination structure-containing compounds, they react with the components in the curable resin composition (b2), and these compounds are firmly held in the electrical insulating layer (B2) formed in the next step, and then formed. In view of the effect that the metal thin film layer is difficult to peel off, imidazoles such as 1- (2-aminoethyl) -2-methylimidazole, pyrazoles such as 1-methyl-5-aminopyrazole, 2,5- Triazoles such as diamino-1,2,4-triazole or triazines such as 2,4-diaminotriazine are preferred. These may have not only an amino group but also a thiol group, a carboxyl group or a cyano group.

(Contact method)
There is no restriction | limiting in the method of making a coordination structure containing compound contact, What is necessary is just to make it physically contact the whole surface of a thermosetting resin composition (b2), or a required part uniformly. Specific examples include a dipping method in which an inner substrate having a resin layer is immersed in a solution of a coordination structure-containing compound in water or an organic solvent, and a spray method in which this solution is sprayed onto the resin layer surface of the inner substrate. It is done. The contact operation may be repeated once or twice or more. The temperature at the time of contact can be arbitrarily selected in consideration of the boiling point, melting point, operability, productivity and the like of the coordination structure-containing compound and the solution thereof, preferably 10 to 100 ° C., more preferably 15 to 65 ° C. The contact time can be arbitrarily selected according to the amount of the coordination structure-containing compound to be attached to the resin layer surface, the concentration of the solution, productivity, etc., preferably 0.1 to 360 minutes, more preferably 0.1 to 60 minutes. Thereafter, in order to remove excess coordination structure-containing compound, an inert gas such as nitrogen can be blown, or the substrate surface can be washed with water or an organic solvent.

(Curing)
The thermosetting resin composition (b2) is cured by the same method as the thermosetting resin composition (b1) described above to form the electrical insulating layer (B2). In the case of forming a multilayer circuit board, an electrical insulating layer (B1) and an electrical insulating layer (B2) are formed before the metal thin film layer is formed in order to connect the conductive layer (A1) and the conductive layer (A2) to be formed later. ) Is formed. This via hole can be formed by chemical processing such as photolithography, or physical processing such as drilling, laser, or plasma etching. In the case of forming a fine pattern, a method using a laser such as a carbon dioxide laser, an excimer laser, or a UV-YAG laser is preferable.

(Conductor layer (A2))
The conductor layer (A2) is formed after the metal thin film layer is formed on the surface of the second electrical insulating layer (B2). Examples of the method for forming the metal thin film layer on the surface of the second electrical insulating layer (B2) include an electroless plating method, a sputtering method, and a vacuum deposition method, and the electroless plating method is preferable.

When forming a metal thin film layer by electroless plating, the surface average roughness Ra of the electrical insulating layer (B2) is adjusted to 0.1 nm to 400 nm before the metal thin film layer is formed on the surface of the electrical insulating layer (B2). It is preferable from the viewpoint of noise reduction in the high frequency region. Here, Ra is the center line average roughness shown in JIS B 0601: 2001. There is no particular limitation on the method for adjusting the surface average roughness of the electrical insulating layer (B2) to the above-mentioned range. .
Examples of the oxidizing compound include known compounds having oxidizing ability, such as inorganic peroxides and organic peroxides; gas; In particular, it is preferable to use an inorganic peroxide or an organic peroxide because it is easy to control the surface average roughness of the electrical insulating layer. Examples of inorganic peroxides include permanganate, chromic anhydride, dichromate, chromate, persulfate, activated manganese dioxide, osmium tetroxide, hydrogen peroxide, periodate, ozone, etc. Examples of the organic peroxide include dicumyl peroxide, octanoyl peroxide, m-chloroperbenzoic acid, and peracetic acid.

  In general, catalyst nuclei such as silver, palladium, zinc and cobalt are adsorbed on the electrically insulating layer (B2) whose surface roughness is adjusted in this way. The method for attaching the catalyst nucleus to the electrical insulating layer (B2) is not particularly limited. For example, an alkaline aqueous solution such as a potassium permanganate aqueous solution or a sodium permanganate aqueous solution is brought into contact with the electrical insulating layer (B2) as necessary. Then, neutralize and reduce with an acidic aqueous solution such as a mixed solution of hydroxyamine sulfate and sulfuric acid, and then add a metal compound such as silver, palladium, zinc, cobalt or a salt or complex thereof with water, alcohol, chloroform, or the like. A method of reducing a metal after being immersed in a solution (which may contain an acid, an alkali, a complexing agent, a reducing agent, etc., if necessary) dissolved in a concentration of 0.001 to 10% by weight in an organic solvent Etc. In particular, when the electrical insulating layer (B2) is formed using the above-described curable composition containing an electrical insulating polymer having an Mw of 10,000 to 1,000,000, the catalyst before the above-described metal thin film layer is formed. Roughening in the adsorption process is highly suppressed, and the electrical insulating layer (B2) is not substantially roughened. Here, it is preferable that the surface average roughness Ra of the electrically insulating layer (B2) on which the catalyst is adsorbed is 0.1 nm to 400 nm.

  As the electroless plating solution used in the electroless plating method, a known autocatalytic electroless plating solution may be used. For example, electroless copper plating solution using ammonium hypophosphite or hypophosphorous acid, ammonium borohydride, hydrazine, formalin, etc. as a reducing agent, electroless nickel-phosphorous plating solution using sodium hypophosphite as a reducing agent Electroless nickel-boron plating solution with dimethylamine borane as reducing agent, electroless palladium plating solution, electroless palladium-phosphorous plating solution with sodium hypophosphite as reducing agent, electroless gold plating solution, electroless silver An electroless plating solution such as an electroless nickel-cobalt-phosphorous plating solution containing sodium hypophosphite as a reducing agent can be used. After the metal thin film layer is formed, the substrate surface can be brought into contact with a rust preventive agent for rust prevention treatment.

  Moreover, in this invention, after forming a metal thin film layer, the said metal thin film layer can be normally heated to 50-350 degreeC, Preferably it is 80-250 degreeC for adhesiveness improvement. Heating may be performed under normal pressure or under pressurized conditions. In the case of heating under pressure, examples of a method for applying pressure include a method for physically applying pressure to the substrate with a hot press machine, a pressure heating roll machine, or the like. The pressure to be applied is preferably 0.1 MPa to 20 MPa, more preferably 0.5 MPa to 10 MPa. The heating is preferably 50 to 350 ° C, more preferably 80 to 250 ° C. If it is this range, the high adhesiveness of a metal thin film and an electrical-insulation layer (B2) is securable.

On the metal thin film layer formed as described above, for example, a plating resist is formed in a pattern according to a conventional method, and then electroplating is performed on the metal thin film layer portion not covered with the plating resist by wet plating such as electrolytic plating. Grow. Thereafter, the plating resist is removed, and the metal thin film layer portion under the plating resist is etched to form a conductor layer (A2). Thus, the conductor layer (A2) is usually composed of a metal thin film layer and plating grown thereon.
The multilayer substrate thus obtained can be used as an inner layer substrate to further increase the number of layers.

  The multilayer circuit board obtained by the method of the present invention is useful as a printed wiring board for mounting a semiconductor element such as a CPU and a memory and other mounting parts in an electronic device such as a computer or a mobile phone. In particular, those having fine wiring are suitable as high-density printed wiring boards, high-speed computers, and wiring boards for portable terminals used in the high-frequency region.

The present invention will be specifically described below with reference to production examples, examples and comparative examples. In the following, “part” is based on mass unless otherwise specified. The test and evaluation were as follows.
(1) Weight average molecular weight (Mw), number average molecular weight (Mn)
It was measured as a polystyrene conversion value by gel permeation chromatography (GPC) using toluene or tetrahydrofuran as a solvent.
(2) Hydrogenation rate and maleic anhydride residue content Hydrogenation rate relative to the number of moles of unsaturated bonds in the polymer before hydrogenation, and maleic anhydride residue relative to the total number of monomer units in the polymer The mole ratio of was measured by ¹ H-NMR spectrum.
(3) Glass transition temperature (Tg) of the polymer
In accordance with JIS K7121: 1987, the temperature was increased by a differential scanning calorimetry (DSC method) at a heating rate of 5 ° C./min.
(4) Resistance to desmear A desmear treatment was performed by immersing the circuit board with via holes in an aqueous solution at 80 ° C. adjusted to a permanganate concentration of 60 g / liter and a sodium hydroxide concentration of 28 g / liter for 15 minutes. The via hole of the circuit board was observed with an optical microscope, and the case where there was no change compared with that before the desmear treatment was evaluated as ○, and the case where a crack (crack) occurred was evaluated as ×.

(5) Flame retardance A portion of the multilayer circuit board for evaluation without a conductor was cut into a strip having a width of 13 mm and a length of 130 mm to prepare a test piece. Methane gas was burned with a Bunsen burner having a tube diameter of 9.5 mm and a tube length of 100 mm, adjusted to a flame with a height of 19 mm, and approached until the obtained specimen was ignited. The flame was removed immediately after ignition and the time during which the test piece was burning was measured. Immediately after the test piece was extinguished, the flame was brought closer until it ignited again. The flame was immediately removed after the second ignition, and the time during which the test piece was burning was measured. When the total of the first burning time and the second burning time of the test piece was within 5 seconds, the test piece was evaluated as “◯”, the case where it exceeded 5 seconds and within 10 seconds, and the case where it exceeded 10 seconds were evaluated as “X”.
(6) Patternability Twenty wiring patterns having a wiring width of 20 μm, a wiring distance of 20 μm, and a wiring length of 10 cm are formed on the electrical insulating layer. The evaluation was evaluated as △ for those with turbulence but no defects, and X for those with defects.

(Production Example 1: Thermosetting resin composition b1)
8-ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene was subjected to ring-opening polymerization, and then hydrogenation reaction was performed to obtain a hydrogenated polymer having Mw 55,800, Mn 31,200, and Tg of about 140 ° C. The hydrogenation rate of the obtained hydrogenated polymer was 99% or more.
100 parts of this hydrogenated polymer, 40 parts of maleic anhydride and 5 parts of dicumyl peroxide were dissolved in 250 parts of t-butylbenzene and reacted at 140 ° C. for 6 hours. The reaction product solution is poured into 1000 parts of isopropyl alcohol to solidify the reaction product, and the resulting solid is vacuum dried at 100 ° C. for 20 hours to obtain a maleic acid-modified hydrogenated alicyclic olefin polymer. It was.
The maleic acid-modified hydrogenated alicyclic olefin polymer had Mw of 68,300, Mn of 33,200, and Tg of 170 ° C. The maleic acid group content was 25 mol%.

  To an organic solvent obtained by mixing 76 parts of dry xylene and 19 parts of dry cyclopentanone, 100 parts of magnesium hydroxide (manufactured by Tateho Chemical Industries, Echo Mag Z-10), titanate coupling agent (KR-138S, Ajinomoto) 5 parts of fine techno) and 171 parts of zirconia beads having a diameter of 1 mm are filled in a zirconia pot, and the centrifugal acceleration is 5 G [disk rotation speed (revolution speed) with a medium planetary mill (P-5, manufactured by Fritsch). 200 rpm, pot rotation speed (autorotation speed) 434 rpm], and stirring was performed for 5 minutes to obtain a flame retardant slurry. When the flame retardant slurry was dried and observed with a scanning electron microscope, the average particle size of the primary particles was 1.0 μm.

  100 parts of the maleic acid-modified hydrogenated alicyclic olefin polymer as an electrically insulating polymer, 40 parts of bisphenol A bis (propylene glycol glycidyl ether) ether as a curing agent, and 1-benzyl-2-phenylimidazole as a curing accelerator 1 part, 5 parts 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] benzotriazole as a laser processability improver, Tris (3,5-di-t as an anti-aging agent -Butyl-4-hydroxybenzyl) -isocyanurate and 150 parts of the flame retardant slurry were dissolved in an organic solvent obtained by mixing 124.9 parts of xylene and 31.2 parts of cyclopentanone, and a planetary stirrer To obtain a thermosetting slurry.

  The thermosetting slurry is applied to a polyethylene naphthalate film with a thickness of 300 μm and a thickness of 75 μm using a die coater, and then dried in a nitrogen oven at 80 ° C. for 10 minutes, with a support having a thickness of 40 μm. A film-like thermosetting resin composition b1 was obtained.

(Production Example 2: Thermosetting resin composition b2)
8-ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene is ^subjected to ring-opening polymerization, followed by hydrogenation reaction, and number average molecular weight (Mn) = 31,200, weight average molecular weight (Mw) = 55,800, Tg = 140 ° C. A hydrogenated polymer was obtained. The hydrogenation rate of the obtained hydrogenated polymer was 99% or more.
100 parts of this hydrogenated polymer and 55 parts of maleic anhydride were dissolved in 233 parts of cyclohexane. After raising the temperature to 135 ° C., a solution prepared by dissolving 5.5 parts of dicumyl peroxide in 105 parts of cyclohexanone was added dropwise over 2 hours, and the reaction was further performed at that temperature for 3 hours. The resulting reaction product solution was diluted with 42 parts of cyclohexanone and 362 parts of toluene and then poured into 2768 parts of isopropyl alcohol to solidify the reaction product, and the resulting solid was vacuum dried at 100 ° C. for 20 hours. Thus, a maleic acid-modified hydrogenated polymer was obtained. The molecular weight of this maleic acid-modified hydrogenated polymer was Mn = 29,000, Mw = 76,000, and Tg was 170 ° C. The maleic acid group content was 29 mol%.

As an electrically insulating polymer, 100 parts of the resulting maleic acid-modified hydrogenated alicyclic olefin polymer, Rikacid TMTA-C (New Nippon Rika as a carboxylic acid anhydride having two or more acid anhydride groups in the molecule) 2 parts), 26.5 parts of a bisphenol F type epoxy resin (EPICLON 830S, manufactured by Dainippon Ink & Chemicals, Inc.) as a polyvalent epoxy compound, 0.1 part of 1-benzyl-2-phenylimidazole as a curing accelerator, 1 part of 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] benzotriazole as a laser processability improver and tris (3,5-di-t-butyl-4 as an anti-aging agent -Hydroxybenzyl) -isocyanurate 1 part and surface average roughness control aid liquid polybutadiene (Ricon 156, manufactured by Sartomer) 30 parts were dissolved in mixed solvent consisting of 337 parts of xylene and cyclopentanone 145 parts, to obtain a curable resin composition by mixing with a planetary stirrer.
The obtained curable resin composition was applied on a polyethylene terephthalate film having a thickness of 300 mm × 300 mm using a die coater and then dried in a nitrogen oven at 80 ° C. for 10 minutes, and the thickness was 3 μm. A film-like thermosetting resin composition b2 with a support was obtained.

(Example 1)
Double-sided copper-clad laminate having a thickness of 1.6 mm (CCL-HL830, manufactured by Mitsubishi Gas Chemical Co., Inc., 18 μm thick on both sides of a core substrate obtained by impregnating glass cloth with a varnish containing glass filler and epoxy resin) Prepare a copper foil affixed to the double-sided copper-clad substrate in a 5% sulfuric acid aqueous solution at 25 ° C. for 1 minute, and then wash with pure water. Corresponding to a substrate having Next, a 0.1% isopropyl alcohol solution of 2,4,6-trimercapto-s-triazine was prepared, and the above core substrate was immersed in this solution at 25 ° C. for 1 minute, and then at 90 ° C. for 15 minutes. The primer layer was formed on the inner layer substrate by drying in the replaced oven.

  Next, the film-like thermosetting resin composition b1 with a support obtained in Production Example 1 was superimposed on the inner layer substrate so that the surface of the resin molded body was on the inside. This was decompressed to 200 Pa using a vacuum laminator equipped with heat-resistant rubber press plates at the top and bottom, and thermocompression bonded at a temperature of 110 ° C. and a pressure of 1.0 MPa for 60 seconds (primary press). Next, the pressure was reduced to 200 Pa using a heat-resistant rubber press plate covered with a metal press plate at the top and bottom, and thermocompression bonded at a temperature of 140 ° C. and a pressure of 1.0 MPa for 60 seconds (secondary press). Thereafter, only the polyethylene naphthalate film was peeled off to obtain an inner layer substrate on which the thermosetting resin composition b1 was laminated. This was left in a nitrogen oven at 170 ° C. for 60 minutes to cure the resin molded body layer to form an electrical insulating layer B1 on the substrate.

  On the surface of the electrical insulating layer B1, the film-like thermosetting resin composition b2 with a support obtained in Production Example 2 was overlaid on the inner layer substrate so that the resin molded body surface was on the inside. This was decompressed to 200 Pa using a vacuum laminator equipped with heat-resistant rubber press plates at the top and bottom, and thermocompression bonded at a temperature of 110 ° C. and a pressure of 1.0 MPa for 60 seconds (primary press). Next, the pressure was reduced to 200 Pa using a heat-resistant rubber press plate covered with a metal press plate at the top and bottom, and thermocompression bonded at a temperature of 140 ° C. and a pressure of 1.0 MPa for 60 seconds (secondary press). Thereafter, only the polyethylene naphthalate film was peeled off to obtain an inner layer substrate having a resin molded body layer on the surface.

  Next, the inner layer substrate having the resin molded body layer on the surface is immersed in a 1.0% aqueous solution of 1- (2-aminoethyl) -2-methylimidazole at 30 ° C. for 10 minutes, and then 1 in 25 ° C. water. After dipping for a minute, the excess solution was removed with an air knife. This is left in a nitrogen oven at 60 ° C. for 30 minutes and 170 ° C. for 60 minutes to dry and cure the resin molded body layer, and on the surface of the inner substrate, the first electrical insulating layer (B1) and the second A circuit board on which the electrical insulating layer (B2) was laminated was obtained.

An interlayer connection via hole having a diameter of 65 μm was formed in the electric insulating layer portion of the obtained circuit board using a carbon dioxide gas laser under the conditions of an output of 0.9 W and a burst mode. Next, the obtained circuit board with a via hole was immersed in an 80 ° C. aqueous solution adjusted to a permanganate concentration of 60 g / liter and a sodium hydroxide concentration of 28 g / liter for 15 minutes for desmear treatment.
Then, the circuit board is immersed twice in a water bath twice, and further subjected to ultrasonic cleaning in another water bath at 25 ° C. for 2 minutes, and then added to a 25 ° C. aqueous solution having a hydroxylamine sulfate concentration of 45 g / liter. The substrate was neutralized and reduced by immersion for 1 minute, and then the circuit board was immersed in a water bath for 1 minute twice and washed with water.
The circuit board after washing with water was immersed in a pre-dip solution [(product name “Sulcup PED-104”, manufactured by Uemura Kogyo Co., Ltd.) 270 g / liter] at 25 ° C. for 1 minute, and then a tin-palladium colloid-containing plating catalyst solution [(product It was immersed for 8 minutes at 30 ° C. in a mixture of 270 g / liter (name “Sulcup PED-104”, manufactured by Uemura Kogyo) and 30 ml / liter (product name “Sulcup PED-105”, manufactured by Uemura Kogyo)). Next, the circuit board was washed with water in the same manner as described above, and then immersed in a catalyst activation solution [(product name “Sulcup AL-106”, trade name, manufactured by Uemura Kogyo Co., Ltd.) 100 ml / liter] at 25 ° C. for 3 minutes, The plating catalyst was activated. Subsequently, the circuit board was washed with water by the same method as described above.
An electroless copper plating solution (product name “Sulcup PSY-1A”, manufactured by Uemura Kogyo Co., Ltd.) 100 ml / liter, (product name “Sulcup PSY-1B”, manufactured by Uemura Kogyo Co., Ltd.) 40 ml / liter And while blowing air into formalin 0.2 mol / L], it was immersed at a temperature of 36 ° C. for 5 minutes and subjected to electroless copper plating to form a conductor layer on the circuit board surface. Subsequently, it was immersed in a rust-preventing solution [product name “AT-21”, manufactured by Uemura Kogyo Co., Ltd., 10 ml / liter] at room temperature for 1 minute, further washed with water in the same manner as described above, dried and subjected to a rust-proofing treatment.

  A dry film of a commercially available photosensitive resist is attached to the rust-proof circuit board by thermocompression bonding, and then a mask for an evaluation pattern is adhered to the dry film for exposure, and then developed to develop a resist pattern. Obtained. Next, it was immersed in an aqueous solution of 50 ml / liter of sulfuric acid at 25 ° C. for 1 minute to remove the rust preventive, and an electrolytic copper plating film having a thickness of 18 μm was formed on the resist non-formed portion by electrolytic copper plating. Thereafter, the resist pattern on the circuit board was removed using a stripping solution, and an etching process was performed with a mixed solution of cupric chloride and hydrochloric acid. Next, the circuit board was heat-treated at 170 ° C. for 30 minutes to obtain a multilayer circuit board with a wiring pattern having two layers on both sides in which a conductor layer composed of the metal thin film and the electrolytic copper plating film was formed on the circuit board. The evaluation results are shown in Table 1.

(Example 2)
A multilayer circuit board was obtained in the same manner as in Example 1 except that the film for buildup wiring (ABF-45H manufactured by Ajinomoto Fine Techno Co., Ltd.) was used instead of the thermosetting resin composition b1. The evaluation results are shown in Table 1.

(Comparative Example 1)
A film-like thermosetting resin composition b2 with a support having a thickness of 10 μm was obtained in the same manner as in Production Example 2 except that the thickness was changed. A multilayer circuit board was obtained in the same manner as in Example 1 except that the film-like thermosetting resin composition b2 with a support having a thickness of 10 μm was used. The evaluation results are shown in Table 1.

(Comparative Example 2)
Before curing the inner layer substrate on which the thermosetting resin composition b1 is laminated, it is immersed in a 1.0% aqueous solution of 1- (2-aminoethyl) -2-methylimidazole at 30 ° C. for 10 minutes, and then at 25 ° C. After immersing in water for 1 minute, the excess solution was removed with an air knife, then dried in a nitrogen oven at 60 ° C. for 30 minutes, and the electrical insulation layer (B2) was not laminated. A multilayer circuit board was obtained in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Comparative Example 3)
A multilayer circuit board was obtained in the same manner as in Example 1, except that 1- (2-aminoethyl) -2-methylimidazole was not immersed in a 1.0% aqueous solution. The evaluation results are shown in Table 1.

  According to the results shown in Table 1, the multilayer circuit board of the present invention was excellent in desmear resistance and flame retardancy, and a fine pattern could be formed. On the other hand, Comparative Example 1 in which the thickness of the electrical insulating layer (B2) not containing the flame retardant with respect to the thickness of the electrical insulating layer (B1) containing the flame retardant is thicker than the range of the present invention is a crack in desmear. Produced. Further, in Comparative Example 2 having no electrical insulating layer (B2), a fine pattern could not be formed. Furthermore, the fine pattern was not able to be formed in the comparative example 3 which was not made to contact with the compound which has a structure which can be coordinated to a metal.

Claims (8)

A first conductor layer (A1), a first electrical insulation layer (B1), a second electrical insulation layer (B2), and a second conductor layer (A2) are laminated in this order on the surface of the inner layer substrate. A multilayer circuit board comprising:
The electrical insulation layer (B1) is an insulation layer obtained by curing a thermosetting resin composition (b1) containing an electrical insulation polymer 1, a curing agent 1, and a filler,
The electrical insulating layer (B2) is substantially free of filler and has a structure capable of coordinating the thermosetting resin composition (b2) containing the electrical insulating polymer 2 and the curing agent 2 to the metal. And is cured after contacting with a compound having
The multilayer circuit board according to claim 1, wherein a thickness of the electrical insulation layer (B2) is 1/5 to 1/50 of a thickness of the electrical insulation layer (B1).   The multilayer circuit board according to claim 1, wherein the electrically insulating polymer 2 has a carboxyl group or an acid anhydride group, and the curing agent 2 is a polyvalent epoxy compound.   The multilayer circuit board according to claim 2, wherein the thermosetting resin composition (b2) further contains a carboxylic acid anhydride having two or more acid anhydride groups in the molecule.   The multilayer circuit board according to any one of claims 1 to 3, wherein the filler is a flame retardant. A first conductor layer (A1), a first electrical insulation layer (B1), a second electrical insulation layer (B2), and a second conductor layer (A2) are laminated in this order on the surface of the inner layer substrate. A multilayer circuit board manufacturing method comprising the following steps (1) to (8):
(1) The thermosetting resin composition (b1) containing the electrically insulating polymer 1, the curing agent 1, and the filler is uncured or semi-cured on the surface of the inner layer substrate having the first conductor layer (A1). Laminating in the state of;
(2) A step of forming the first electrical insulating layer (B1) by curing the thermosetting resin composition (b1);
(3) A thermosetting resin composition (b2) containing substantially no filler and containing the electrically insulating polymer 2 and the curing agent 2 on the surface of the first electrically insulating layer (B1). Laminating in an uncured or semi-cured state and at a thickness of 1/5 to 1/50 of the thickness of the electrical insulating layer (B1);
(4) A step of bringing the surface of the thermosetting resin composition (b2) into contact with a compound having a structure capable of coordinating with a metal;
(5) Next, the step of forming the second electrically insulating layer (B2) by curing the thermosetting resin composition (b2);
(6) forming a metal thin film layer on the surface of the second electrical insulating layer (B2);
(7) A step of forming a second conductor layer (A2) including the metal thin film layer.   The method for producing a multilayer circuit board according to claim 5, wherein the electrically insulating polymer 2 has a carboxyl group or an acid anhydride group, and the curing agent 2 is a polyvalent epoxy compound.   The method for producing a multilayer circuit board according to claim 6, wherein the thermosetting resin composition (b2) further contains a carboxylic acid anhydride having two or more acid anhydride groups in the molecule. .   The method for manufacturing a multilayer circuit board according to any one of claims 5 to 7, wherein the filler is a flame retardant.