JP2009155355A - Resin composition for insulating layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition suitable for forming an insulating layer of a multilayered printed wiring board or the like, excellent in heat resistance, mechanical strength and laminating performance, and having low thermal expansion coefficient. <P>SOLUTION: This resin composition contains (A) a polymer of a bismaleimide compound and a diamine compound, (B) an epoxy resin having two or more of epoxy groups in one molecule, (C) a curing agent, and (D) one or more kinds of resins selected from the group of phenoxy resins and polyvinyl acetal resins. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin composition suitable for forming an insulating layer such as a multilayer printed wiring board.

  In recent years, downsizing and higher performance of electronic devices have progressed, and multilayering of printed wiring boards and higher density of wiring have progressed. As the number of layers increases, it is necessary to reduce the thickness of the printed wiring board while maintaining the mechanical strength (strength at break and elongation at break). In addition, in order to maintain connection reliability in increasing the density of wiring, the material forming the insulating layer is required to have high heat resistance. In addition, multilayer printed wiring boards with high-density wiring tend to cause problems such as cracking due to the difference in thermal expansion coefficient between copper wiring and insulating layer, so it is required to keep the thermal expansion coefficient of insulating layer low. The

  As an insulating material excellent in mechanical strength and heat resistance, for example, Patent Document 1 discloses a resin composition comprising a maleimide compound, an epoxy resin, a curing agent, and a polyvinyl acetal resin. However, when a resin composition that is generally excellent in mechanical strength and heat resistance is used as a sheet-like laminated material such as an adhesive film or a prepreg, and the resin composition is used by being laminated on an inner circuit board in a dry or semi-cured state, There is a problem that the laminating performance is low.

  On the other hand, as an insulating material having a low coefficient of thermal expansion, for example, Patent Document 2 discloses a resin composition containing a large amount of silica. In a resin composition highly filled with silica, there is a problem that the drilling workability such as via holes deteriorates. However, due to the advancement of laser technology and the like, even when using a resin composition highly filled with silica, a multilayer with drilling is required. Production of printed wiring boards is possible. However, the drilling workability is inevitably lowered as compared with a system in which silica is not blended or a small amount is blended. In addition, via holes tend to have smaller diameters due to higher wiring density, in which case the problem of drilling workability becomes more prominent. Therefore, in order to improve the productivity of the multilayer printed wiring board or to further reduce the thermal expansion coefficient of the insulating layer, a technique for reducing the thermal expansion coefficient by a method different from the high filling of silica has been desired.

Japanese Patent Laid-Open No. 11-5828 JP 2005-154727 A

  The present invention provides a resin composition suitable for forming an insulating layer such as a multilayer printed wiring board, which is excellent in heat resistance and mechanical strength, and at the same time has excellent laminating properties, and further has a low thermal expansion coefficient. For the purpose.

  As a result of intensive studies by the present inventors, a polymer of a bismaleimide compound and a diamine compound, an epoxy resin having two or more epoxy groups in a molecule, a curing agent, and (D) a phenoxy resin and a polyvinyl acetal resin are selected. It has been found that the above-mentioned problems can be solved by a resin composition containing one or more kinds of resins, and the present invention has been completed.

That is, the present invention includes the following contents.
[1] (A) Polymer of bismaleimide compound and diamine compound, (B) Epoxy resin having two or more epoxy groups in one molecule, (C) curing agent, and (D) phenoxy resin and polyvinyl acetal resin 1 or more types of resin selected from these, The resin composition characterized by the above-mentioned.
[2] When the nonvolatile content of the resin composition is 100% by mass, the content of the component (A) is 10 to 50% by mass, the content of the component (B) is 15 to 45% by mass, and the component (C) The resin composition according to the above [1], wherein the content is 3 to 20% by mass and the content of the component (D) is 10 to 50% by mass.
[3] An adhesive film in which the epoxy resin composition according to [1] or [2] is formed on a support film.
[4] An adhesive film with a copper foil in which the resin composition according to the above [1] or [2] is layered on the copper foil.
[5] A prepreg in which the epoxy resin composition according to the above [1] or [2] is impregnated in a sheet-like reinforcing substrate made of fibers.
[6] A multilayer printed wiring board in which an insulating layer is formed of a cured product of the epoxy resin composition according to [1] or [2].

  According to the present invention, there is provided a resin composition having excellent mechanical strength and at the same time excellent laminate performance. Moreover, since the resin composition of this invention also has a low coefficient of thermal expansion, it is suitably used as a resin composition for forming an insulating layer of a multilayer printed wiring board.

  Hereinafter, the present invention will be described in more detail.

[Component (A) Bismaleimide Compound and Diamine Compound Polymer]
The polymer of the component (A) bismaleimide compound and diamine compound in the present invention can be obtained by Michael addition reaction of an aromatic or aliphatic primary diamine compound or secondary diamine compound to a bismaleimide compound. it can.

  As the bismaleimide compound, an aromatic bismaleimide compound having an aromatic ring structure is preferable from the viewpoint of heat resistance and thermal expansion coefficient. Examples of the aromatic bismaleimide compound include N, N ′-(1,3-phenylene) bismaleimide, N, N ′-(1,4-phenylene) bismaleimide, N, N ′-[1,3- ( 2-methylphenylene)] bismaleimide, bis (4-maleimidophenyl) methane, bis (3-methyl-4-maleimidophenyl) methane, bis [4- (4-maleimidophenoxy) phenyl] methane, bis (3-ethyl -5-methyl-4-maleimidophenyl) methane, 1,1-bis [4- (3-maleimidophenoxy) phenyl] ethane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] ethane, 1, 2-bis [4- (3-maleimidophenoxy) phenyl] ethane, 1,2-bis [4- (4-maleimidophenoxy) phenyl] ethane, 2,2-bis [4 (4-maleimidophenoxy) phenyl] propane, 2,2-bis [4- (3-maleimidophenoxy) phenyl] butane, 2,2-bis [4- (4-maleimidophenoxy) phenyl] butane, 1,4- Bis (4-maleimidophenyl) cyclohexane, 1,4-bis (maleimidomethyl) benzene, 1,3-bis (3-maleimidophenoxy) benzene, 1,4-bis [4- (4-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3-maleimidophenoxy) -α, α- Dimethylbenzyl] benzene, 1,3-bis [4- (3-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis 4- (4-Maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-maleimidophenoxy) -3,5-dimethyl-α, α-dimethyl Benzyl] benzene, 1,4-bis [4- (3-maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (3-maleimidophenoxy) -3 , 5-dimethyl-α, α-dimethylbenzyl] benzene, 4,4′-bis (3-maleimidophenoxy) biphenyl, 4,4′-bis (4-maleimidophenoxy) biphenyl, bis (4-maleimidophenyl) ketone Bis [4- (3-maleimidophenoxy) phenyl] ketone, bis [4- (4-maleimidophenoxy) phenyl] ketone, bis (4-maleimi Phenyl) sulfide, bis [4- (3-maleimidophenoxy) phenyl] sulfide, bis [4- (4-maleimidophenoxy) phenyl] sulfide, bis [4- (3-maleimidophenoxy) phenyl] sulfoxide, bis [4- (4-maleimidophenoxy) phenyl] sulfoxide, bis (4-maleimidophenyl) sulfone, bis [4- (3-maleimidophenoxy) phenyl] sulfone, bis [4- (4-maleimidophenoxy) phenyl] sulfone, bis (4 -Maleimidophenyl) ether, bis [4- (3-maleimidophenoxy) phenyl] ether, bis [4- (4-maleimidophenoxy) phenyl] ether and the like.

  As the diamine compound, a primary diamine compound is preferable from the viewpoint of reactivity with the bismaleimide compound, and an aromatic diamine compound having an aromatic ring structure is preferable from the viewpoint of heat resistance and thermal expansion coefficient. Preferred diamine compounds include 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, and 4,4′-bis (3-aminophenoxy). Biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, 3-bis (3-aminophenoxy) benzene, 4-bis (4-aminophenoxy) benzene, bis (3- (3-aminophenoxy) phenyl) Ether, bis (4- (4-aminophenoxy) phenyl) ether, 3-bis (3- (3-aminophenoxy) phenoxy) benzene, 4-bis (4- (4-aminophenoxy) phenoxy) benzene, bis ( 3- (3- (3-aminophenoxy) phenoxy) phenyl) ether, bis ( -(4- (4-aminophenoxy) phenoxy) phenyl) ether, 3-bis (3- (3- (3-aminophenoxy) phenoxy) phenoxy) benzene, 4-bis (4- (4- (4-amino Phenoxy) phenoxy) phenoxy) benzene, 2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 4′-bis (3-amino) Benzyl) biphenyl, 4′-bis (4-aminobenzyl) biphenyl, 3-bis (3-aminobenzyl) benzene, 4-bis (4-aminobenzyl) benzene, 3-bis (α, α-dimethyl-3-) Aminobenzyl) benzene, 1,4-bis (α, α-dimethyl-3-aminobenzyl) benzene, 3-bis (α, α-dimethyl-4-aminobenzene) Jill) benzene, and the like. The diamine compounds may be used alone or in combination of two or more.

  The reaction between the bismaleimide compound and the diamine compound can be carried out according to a known method (see JP-A-3-14836, etc.). The amount of the diamine compound used is preferably 1 to 4 molar equivalents, more preferably 2 to 3.5 molar equivalents, relative to 1 mol of the bismaleimide compound. The reaction is usually carried out by reacting in the range of 100 to 250 ° C., preferably 170 ° C. to 200 ° C. for several minutes to several hours. Examples of the solvent used for the reaction include polar solvents such as N, N-dimethylformamide and N-methylpyrrolidone. In order to control the reaction rate, a radical scavenger, an anionic polymerization catalyst, a radical generator, a Michael addition reaction accelerator or the like can be used as a catalyst as necessary. The addition amount of the catalyst is usually 0.001 to 5% by mass with respect to the total mass of the bismaleimide compound and the diamine compound.

  The mass average molecular weight of the polymer of the bismaleimide compound and the diamine compound is preferably 600 to 3500 from the viewpoint of solubility in organic solvents and mechanical strength. In addition, the mass mean molecular weight in this invention is measured by the gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the number average molecular weight by the GPC method is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K-804L / K manufactured by Showa Denko KK as a column. -804L can be measured using chloroform as a mobile phase at a column temperature of 40 ° C. and calculated using a standard polystyrene calibration curve. The softening point of the resin composition is preferably 40 to 150 ° C. from the viewpoint of laminating properties.

  Examples of commercially available polymers of bismaleimide compounds and diamine compounds include “Techmite E2020” (N, N ′-(4,4′-diphenylmethane) bismaleimide and 1,3 manufactured by Printec Co., Ltd. -A polymer of bis (α, α-dimethyl-4-aminobenzyl) benzene, a weight average molecular weight of 1500 to 2000, and a softening point of 103 to 118 ° C.

  The content of the polymer of the bismaleimide compound and the diamine compound is preferably 10 to 50% by mass when the nonvolatile content of the resin composition of the present invention is 100% by mass. A polymer of a bismaleimide compound and a diamine compound may be used alone or in combination of two or more.

[Epoxy resin having two or more epoxy groups in one molecule of component (B)]
The “epoxy resin having two or more epoxy groups in one molecule” of the component (A) in the present invention is an aromatic epoxy resin having an aromatic ring skeleton in the molecule from the viewpoint of thermal expansion coefficient and heat resistance. preferable. Preferred epoxy resins include, for example, cresol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, biphenyl type epoxy resins, naphthalene type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins. Bisphenol S type epoxy resin, fluorene type epoxy resin, xanthene type epoxy resin, dicyclopentadiene type epoxy resin, anthracene type epoxy resin. The epoxy resins may be used alone or in combination of two or more.

  The epoxy resin as component (B) preferably contains an epoxy resin that is liquid at a temperature of 20 ° C. from the viewpoint of laminating properties and mechanical strength. The content of the liquid epoxy resin is preferably 20 to 100% by mass when the epoxy resin of the component (B) is 100% by mass.

  Examples of commercially available liquid epoxy resins include HP4032 (naphthalene type epoxy resin, epoxy equivalent 149), HP4032D (naphthalene type epoxy resin, epoxy equivalent 141) manufactured by Dainippon Ink and Chemicals, Japan epoxy resin ( Epicoat 807 (bisphenol F type epoxy resin, epoxy equivalent 170), Epicoat 828EL (bisphenol A type epoxy resin, epoxy equivalent 189)), Epicoat 152 (phenol novolac type epoxy resin, epoxy equivalent 174), etc. .

  Examples of commercially available solid epoxy resins include HP4700 (naphthalene type epoxy resin, epoxy equivalent 163), N-690 (cresol novolak type epoxy resin, epoxy equivalent 208) manufactured by Dainippon Ink and Chemicals, N-695 (cresol novolac type epoxy resin, epoxy equivalent 208), Nippon Kayaku Co., Ltd. EPPN-502H (trisphenol epoxy resin, epoxy equivalent 168), NC7000L (naphthol novolac type epoxy resin, epoxy equivalent 228), NC3000H (Biphenyl type epoxy resin, epoxy equivalent 290), ESN185 manufactured by Tohto Kasei Co., Ltd. (naphthol novolak type epoxy resin, epoxy equivalent 275), ESN475 (naphthol novolak type epoxy resin, epoxy equivalent 350), etc. It is.

  The content of the epoxy resin is preferably 15 to 45% by mass, more preferably 20 to 40% by mass, particularly preferably 25 when the nonvolatile content of the resin composition in the present invention is 100% by mass. It is -35 mass%.

[Curing agent for component (C)]
As the curing agent of the component (C) in the present invention, an amine curing agent, a guanidine curing agent, an imidazole curing agent, a phenol curing agent, an acid anhydride curing agent, a hydrazide curing agent, a carboxylic acid curing agent. And thiol-based curing agents or epoxy adducts or microcapsules thereof. A phenolic curing agent is particularly preferable as the curing agent. Examples of phenolic curing agents include phenol novolac resins, alkylphenol novolak resins, triazine structure-containing phenol novolak resins, bisphenol A novolak resins, dicyclopentadiene structure-containing phenol resins, xylok type phenol resins, terpene-modified phenol resins, Examples thereof include polyvinylphenols, naphthalene structure-containing phenolic curing agents, fluorene structure-containing phenolic curing agents, and the like. Specific examples of commercially available phenolic curing agents include “Phenolite LA7054” and “Phenolite EXB9889” manufactured by Dainippon Ink & Chemicals, Inc. Each of the curing agents may be used alone or in combination of two or more.

  The content of the curing agent of the component (C) is preferably 3 to 20% by mass and more preferably 6 to 15% by mass when the nonvolatile content of the resin composition of the present invention is 100% by mass. preferable. When the content of the curing agent is outside this range, the thermal expansion coefficient tends to increase or the mechanical strength tends to decrease.

  If necessary, an organic phosphine compound such as triphenylphosphine, an imidazole compound such as 2-ethyl 4-methylimidazole, and the like may be added to the resin composition of the present invention as a curing accelerator. When using a hardening accelerator, it is preferable to use it in the range of 0.5-2 mass% when the compounding quantity is 100 mass%.

[Phenoxy resin or polyvinyl acetal resin of component (D)]
Examples of the phenoxy resin in the present invention include bisphenol type phenoxy resin (phenoxy resin having a bisphenol skeleton in the molecule), novolac type phenoxy resin (phenoxy resin having a novolak skeleton in the molecule), naphthalene type phenoxy resin (intra molecule). Phenoxy resins such as a phenoxy resin having a naphthalene skeleton) and a biphenyl type phenoxy resin (a phenoxy resin having a biphenyl skeleton in the molecule) can be given. The phenoxy resin can be obtained by reacting a bifunctional epoxy resin with a bisphenol compound. Each of the phenoxy resins may be used alone or in combination of two or more. The phenoxy resin is particularly preferably a biphenyl type phenoxy resin from the viewpoint of heat resistance and moisture resistance. Although the weight average molecular weight of a thermoplastic resin is not specifically limited, Preferably it is 5000-100000.

  Examples of commercially available phenoxy resins include Phenototo YP50 (bisphenol A type phenoxy resin) manufactured by Toto Kasei Co., Ltd., E-1256 (bisphenol A type phenoxy resin) manufactured by Japan Epoxy Resin Co., Ltd., FX280 manufactured by Toto Kasei Co., Ltd. FX293 (fluorene type phenoxy resin), Japan Epoxy Resin Co., Ltd. YX8100, YL6954, YL6974 (biphenyl type phenoxy resin), etc. are mentioned.

  Examples of the polyvinyl acetal resin in the present invention include a polyvinyl formal resin and a polyvinyl acetal resin. The polyvinyl acetal resin can be obtained by condensation of polyvinyl alcohol and an aldehyde, and has an acetal bond in the molecule. When formaldehyde is used as the aldehyde, a polyvinyl formal resin can be obtained, and when butyraldehyde is used as the aldehyde, a polyvinyl butyral resin can be obtained. Polyvinyl acetal resins may be used alone or in combination of two or more.

  Specific examples of the polyvinyl acetal resin include those manufactured by Denki Kagaku Kogyo Co., Ltd., electrified butyral 4000-2, 5000-A, 6000-C, 6000-EP, Sekisui Chemical Co., Ltd., ESREC BH series, BX series, KS. Series, BL series, BM series and the like.

  The polyvinyl acetal resin preferably has a glass transition temperature of 80 ° C. or higher. The “glass transition temperature” here is determined according to the method described in JIS K7197. When the glass transition temperature is higher than the decomposition temperature and the glass transition temperature is not actually observed, the decomposition temperature can be regarded as the glass transition temperature in the present invention. The decomposition temperature is defined as the temperature at which the mass reduction rate is 5% when measured according to the method described in JIS K 7120.

  In the resin composition of the present invention, the content of the phenoxy resin or the polyvinyl acetal resin as the component (D) is preferably 10 to 50% by mass when the nonvolatile content of the resin composition is 100% by mass. More preferably, it is -35 mass%. When the content ratio of the component (C) is too small, the coefficient of thermal expansion tends to increase and the mechanical strength tends to decrease. When the content ratio is too large, the laminate performance tends to decrease. A mixture of phenoxy resin and polyvinyl acetal resin may be used.

  The resin composition of the present invention may contain components other than those described above as long as the effects of the present invention are exhibited. For example, a radical polymerization initiator such as dicumyl peroxide and an aromatic carboxylic acid such as benzoic acid may be added as a curing catalyst. The addition amount in this case is preferably in the range of 0.001 to 5% by mass with respect to 100% by mass of the polymer of the bismaleimide compound and the diamine compound. Further, for example, an inorganic filler such as silica may be contained for the purpose of further reducing the coefficient of thermal expansion. When an inorganic filler is contained, the blending amount may be appropriately adjusted within a range that does not cause inconvenience in drilling workability such as via holes. Moreover, for example, other resin components such as a thermoplastic resin such as a phenoxy resin and polyvinyl acetal may be contained. In addition, for example, for the purpose of imparting flame retardancy, a flame retardant such as an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, or a metal hydroxide may be contained. Also, for example, organic fillers such as silicon powder, nylon powder and fluorine powder, thickeners such as olben and benton, silicone type, fluorine type, polymer type antifoaming agent or leveling agent, imidazole type, thiazole type, triazole type Further, an adhesiveness-imparting agent such as a silane coupling agent, or a resin additive such as a colorant such as phthalocyanine / blue, phthalocyanine / green, iodin / green, disazo yellow, or carbon black may be contained.

  The total content of components (A) to (D) in the resin composition of the present invention is not particularly limited, but is usually 50 to 50% with respect to the resin composition (non-volatile content: 100% by mass). The range is 100% by mass.

  The resin composition of the present invention is, for example, applied on a support film to form a resin composition layer to form an adhesive film, and applied to a copper foil to form a resin composition layer to form an adhesive film with copper foil. Alternatively, a prepreg can be obtained by impregnating the resin composition into a sheet-like reinforcing base made of fibers. The resin composition of the present invention can be applied to a circuit board in a varnish state to form an insulating layer, but industrially, the insulating layer is generally formed in the form of the above adhesive film, adhesive film with copper foil or prepreg. It is preferable to use for.

  The resin composition of the present invention can be applied to a circuit board in a varnish state to form an insulating layer, but industrially generally, an adhesive film, an adhesive film with copper foil, a sheet-like laminated material such as a prepreg, etc. It is preferably used in the form.

  The adhesive film and the adhesive film with copper foil of the present invention are prepared by a method known to those skilled in the art, for example, by preparing a resin varnish in which a resin composition is dissolved in an organic solvent, and using the support film or copper foil as a support. And then drying the organic solvent by heating or blowing hot air to form a resin composition layer.

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and carbitols such as cellosolve and butyl carbitol. And aromatic hydrocarbons such as toluene and xylene, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and the like. Two or more organic solvents may be used in combination.

  The drying conditions are not particularly limited, but the drying is performed so that the content of the organic solvent in the resin composition layer is usually 10% by mass or less, preferably 5% by mass or less. Although it depends on the amount of organic solvent in the varnish and the boiling point of the organic solvent, it is prepared, for example, by drying a varnish containing 30 to 60% by mass of an organic solvent at 50 to 150 ° C for about 3 to 10 minutes. Those skilled in the art can appropriately set suitable drying conditions through simple experiments.

  The thickness of the resin composition layer formed in the adhesive film and the adhesive film with copper foil is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm. The resin composition layer may be protected by a protective film described later. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches.

  Examples of the support film and protective film in the present invention include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyesters such as polyethylene naphthalate, polycarbonate, polyimide, Can include release paper, copper foil, metal foil such as aluminum foil, and the like. In addition, the support film and the protective film may be subjected to a release treatment in addition to the mud treatment and the corona treatment.

  Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers. The thickness of the protective film is not particularly limited, but is usually 1 to 40 μm, preferably 10 to 30 μm.

  As copper foil in the adhesive film with copper foil of the present invention, in addition to electrolytic copper foil, rolled copper foil, etc., ultrathin copper foil with carrier, peelable film such as polyethylene terephthalate subjected to release treatment, copper What formed the vapor deposition layer etc. can be used.

  The thickness of the copper foil is usually preferably 9 to 35 μm. In the case of an ultrathin copper foil with a carrier, a copper foil of 1 to 5 μm is preferably used. Moreover, in the case of the copper vapor deposition film in which the copper vapor deposition layer was formed in the peelable film, the thickness of the vapor deposition layer is usually 100 to 5000 mm.

  In order that the copper foil used for this invention may improve the adhesive strength by a throwing effect, it is preferable that the surface by which the curable resin composition of this invention is layered is roughened. The method of the roughening treatment is not particularly limited. For example, the method of roughening by etching or the copper foil is immersed in an aqueous copper sulfate solution, and copper is deposited by electrolysis to form fine copper particles on the surface of the copper foil. It can carry out by well-known methods, such as the method of doing. Moreover, after a surface roughening process, you may give a rust prevention process or the process which improves adhesiveness with resin, such as a chromate process and a blackening process. From the viewpoint of suppressing transmission loss, the surface roughness (Rz) of the copper foil is preferably 6.0 μm or less, more preferably 4.0 μm or less, and even more preferably 3.0 μm or less. In addition, the surface roughness in this invention is defined by the ten-point average roughness of JIS B 0601-1994 “Definition of surface roughness”.

  Commercially available copper foils include JTC-LP foil, JTC-AM foil (all manufactured by Nikko Materials Co., Ltd.), GTS-MP foil, F2-WS foil (all manufactured by Furukawa Circuit Foil Co., Ltd.). Etc.

  Next, a method for producing the multilayer printed wiring board of the present invention using the adhesive film of the present invention will be described. When the resin composition layer is protected with a protective film, the resin composition layer is peeled and then laminated on one or both sides of the circuit board so that the resin composition layer is in direct contact with the circuit board. In the adhesive film of the present invention, a method of laminating on a circuit board under reduced pressure by a vacuum laminating method is preferably used. The laminating method may be a batch method or a continuous method using a roll. Further, the adhesive film and the circuit board may be heated (preheated) as necessary before lamination.

  As the substrate used for the circuit substrate, a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, or the like can be used. In the present invention, the circuit board refers to a circuit board formed with a patterned conductor layer (circuit) on one or both sides of the board. The circuit board referred to in the present invention includes a conductor layer (circuit) in which one or both surfaces of the outermost layer of the multilayer printed wiring board are patterned. The surface of the conductor layer may be previously roughened by blackening or the like.

The laminating conditions are preferably a pressure bonding temperature (laminating temperature) of 70 to 140 ° C. and a pressure bonding pressure of preferably 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ). Lamination is preferably performed under a reduced pressure of 20 mmHg (26.7 hPa) or less. The vacuum lamination can be performed using a commercially available vacuum laminator. Commercially available vacuum laminators include, for example, a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a vacuum pressurizing laminator manufactured by Meiki Seisakusho Co., Ltd., a roll dry coater manufactured by Hitachi Industries, Ltd., and Hitachi AIC Co., Ltd. ) Made vacuum laminator and the like.

  After laminating the adhesive film on the circuit board, the support film is peeled off. For example, when a release film is used, the support film may be peeled after curing. An insulating layer can be formed on the circuit board by thermosetting. The conditions for thermosetting are selected in the range of 20 to 180 minutes at 150 to 220 ° C, more preferably 30 to 120 minutes at 160 to 200 ° C.

  If the support film is not peeled off after the insulating layer is formed, it is peeled off here. If necessary, a via hole and a through hole are formed by drilling an insulating layer formed on the circuit board. Drilling can be performed by a known method such as drilling, laser, or plasma, or a combination of these methods if necessary. However, drilling by a laser such as a carbon dioxide laser or YAG laser is the most common method. .

  Next, a conductor layer is formed by plating. As the plating, for example, dry plating such as vapor deposition, sputtering, or ion plating can be used. As a subsequent pattern formation method, for example, a subtractive method or a semi-additive method known to those skilled in the art can be used.

  The roughness of the roughened surface obtained by roughening the surface of the insulating layer (surface roughness Ra value) is preferably 0.5 μm or less, more preferably 0.35 μm or less in forming fine wiring. preferable. In addition, the surface roughness Ra value in this invention is the value which calculated | required Ra (10-point average roughness) using the non-contact-type surface roughness meter (WYKO NT3300 by Beeco Instruments). The Ra value is an average value of the heights calculated over the entire measurement region. Specifically, the Ra value is an arithmetic average obtained by measuring the absolute value of the height changing in the measurement region from the surface as an average line. Yes, it can be expressed by the following formula (1). Here, M and N are the number of data in each direction of the array.

  When the adhesive film with copper foil is used, circuit formation can be performed by patterning the copper foil as a conductor layer by a subtractive method using etching. In addition, in the case of the above-described ultrathin copper foil with a carrier or an adhesive film with a copper foil using a copper vapor-deposited film as a support, a circuit can be formed by a semi-additive method. In addition, after removing copper foil by an etching, according to the above-mentioned method, a conductor layer can also be formed by plating on the insulating layer surface.

  The prepreg of the present invention can be produced by impregnating the resin composition of the present invention into a sheet-like reinforcing substrate made of fibers by a hot melt method or a solvent method and semi-curing by heating. That is, it can be set as the prepreg which will be in the state which the resin composition of this invention impregnated the sheet-like reinforcement base material which consists of fibers. As the sheet-like reinforcing substrate made of fibers, for example, those commonly used as prepreg fibers such as glass cloth and aramid fibers can be used.

  In the hot melt method, without dissolving the resin in an organic solvent, the resin is once coated on the resin and a coated paper having good releasability, and then laminated on a sheet-like reinforcing substrate or directly applied by a die coater. Thus, a prepreg is manufactured. Similarly to the adhesive film, the solvent method is a method in which a sheet-like reinforcing base material is immersed in a resin varnish in which a resin is dissolved in an organic solvent, the resin varnish is impregnated into the sheet-like reinforcing base material, and then dried.

Next, a method for producing the multilayer printed wiring board of the present invention using the prepreg of the present invention will be described. One or several prepregs of the present invention are stacked on a circuit board, a metal plate is sandwiched through a release film, and press lamination is performed under pressure and heating conditions. The pressure is preferably 5 to 40 kgf / cm ² (49 × 10 ^{4 to} 392 × 10 ⁴ N / m ² ), and the temperature is preferably 120 to 200 ° C. for 20 to 100 minutes. Moreover, it can also be manufactured by laminating on a circuit board by a vacuum laminating method as in the case of an adhesive film, and then curing by heating. After that, after the surface of the cured prepreg is roughened as in the method described above, a multilayer printed wiring board can be manufactured by forming a conductor layer by plating.

  The present invention will be described in more detail with reference to the following examples and comparative examples, but these are not intended to limit the present invention in any way.

  15 parts by mass of a bisphenol F type epoxy resin (“Epicoat 807” manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent of about 170), a triazine ring-containing phenol novolak resin (“Phenolite EX9889” manufactured by Dainippon Ink & Chemicals, Inc.) , Phenol equivalent approximately 120) 8 parts by mass, biphenyl-containing phenoxy resin (“YX8100” manufactured by Japan Epoxy Resin Co., Ltd., nonvolatile content 30% by weight) 33 parts by mass, polymer of bismaleimide compound and diamine compound ((stock) ) 20 parts by mass of Printec Co., Ltd. “E2020”), 0.16 parts by mass of a radical polymerization initiator (Nippon Yushi Co., Ltd. “Park Mill D”), 6 parts by mass of N, N-dimethylacetamide were mixed and dissolved. A thermosetting resin composition varnish was prepared by uniformly dispersing with a high-speed rotating mixer. Next, such a resin varnish was uniformly applied on a polyethylene terephthalate (thickness 38 μm, hereinafter abbreviated as PET) with a die coater so that the resin thickness after drying was 40 μm, and was 80 to 120 ° C. (average 100 ° C. ) For 6 minutes (residual solvent amount of about 4% by mass). Subsequently, it wound up in roll shape, bonding a 15-micrometer-thick polypropylene film on the surface of a resin composition. The roll-like adhesive film was slit to a width of 507 mm, and a sheet-like adhesive film having a size of 507 × 336 mm was obtained therefrom.

  The bisphenol F-type epoxy resin of Example 1 was replaced with a naphthalene-type epoxy resin (“HP4032” manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent of about 149), and 33 parts of a biphenyl-containing phenoxy resin was added to a fluorene skeleton-containing phenoxy resin (Toto An adhesive film was obtained in exactly the same manner except that it was changed to 28 parts of a 40% by weight non-volatile content methyl ethyl ketone solution of “FX293” manufactured by Kasei Co., Ltd.

  33 parts of the biphenyl-containing phenoxy resin of Example 1 was changed to 40 parts of a 1: 1 mixed solution of ethanol and toluene having a nonvolatile content of 15% by weight of a polyvinyl acetal resin (“BX-5” manufactured by Sekisui Chemical Co., Ltd.). Except for the above, an adhesive film was obtained in exactly the same manner.

<Comparative Example 1>
Polymer of aromatic bismaleimide and aromatic diamine described in Example 1 is 20 parts by mass of bis (3-ethyl-5-methyl-4-maleimidophenyl) methane (Kei Kasei Co., Ltd. “BMI-70”). An adhesive film was obtained in exactly the same manner except that

<Comparative example 2>
Polymer of aromatic bismaleimide and aromatic diamine described in Example 2 was added in an amount of 20 parts by mass of bis (3-ethyl-5-methyl-4-maleimidophenyl) methane (Kei Kasei Co., Ltd. “BMI-70”). An adhesive film was obtained in exactly the same manner except that

<Evaluation of Tg (glass transition temperature) and thermal expansion coefficient by TMA method>
From the adhesive films obtained in Examples and Comparative Examples, the polypropylene film was peeled off and laminated on a copper foil (“JTC-LP foil” manufactured by Nikko Materials Co., Ltd.) using a vacuum laminator. Subsequently, PET was peeled off and heated at 190 ° C. for 90 minutes to obtain a cured product of the resin composition with copper foil. Thereafter, the copper foil was removed with ferric chloride (manufactured by Tsurumi Soda Co., Ltd.), washed with water and dried at 130 ° C. for 15 minutes to obtain a cured product of the resin composition. The obtained cured product was cut into test pieces having a width of about 5 mm and a length of about 15 mm, and thermomechanical analysis was performed by a tensile load method using a thermomechanical analyzer manufactured by Rigaku Corporation (Thermo Plus TMA8310). After mounting the test piece on the apparatus, the test piece was measured twice continuously under the measurement conditions of a load of 1 g and a heating rate of 5 ° C./min. The average coefficient of linear expansion from 25 ° C. to 150 ° C. in the second measurement was calculated and used as the value of the thermal expansion coefficient. In addition, the second value of Tg was used.

<Evaluation of strength at break and elongation at break>
From the adhesive films obtained in Examples and Comparative Examples, the polypropylene film was peeled off and laminated on a copper foil (“JTC-LP foil” manufactured by Nikko Materials Co., Ltd.) using a vacuum laminator. Subsequently, PET was peeled off and heated at 190 ° C. for 90 minutes to obtain a cured product of the resin composition with copper foil. Thereafter, the copper foil was removed with ferric chloride (manufactured by Tsurumi Soda Co., Ltd.), washed with water and dried at 130 ° C. for 15 minutes to obtain a cured product of the resin composition. In accordance with JIS K7172, dumbbell-shaped test pieces were cut out and a tensile test was performed using these test pieces. From the results, the strength at break and elongation at break of the cured product were calculated.

<Evaluation of laminating properties>
A double-sided wiring board in which comb-teeth wiring with a conductor thickness of 35 μm and L / S = 160 μm / 160 μm is formed on a glass epoxy substrate with a board thickness of 0.4 mm is prepared so that the copper surface roughness is 2 μm. The roughening process was performed using "CZ8100" manufactured by Co., Ltd. The adhesive films produced in Examples and Comparative Examples on the substrate were vacuum pressure type laminator manufactured by Meiki Seisakusho Co., Ltd., MLP-500, with a vacuum degree of 0.75 mmHg, a pressure bonding temperature of 130 ° C., and a pressure bonding pressure. The resin composition layer was laminated by pressing for 30 seconds under the condition of 58.8 × 10 ⁴ N / m ² . After the lamination, the PET was peeled off and thermally cured at 190 ° C. for 60 minutes to form an insulating layer. The comb-tooth wiring portion of the printed wiring board on which the insulating layer was formed was cut. Using a Keyence microscope, VK8510, cross-sectional observation was performed to determine the unevenness of the insulating layer. As shown in FIG. 1, the unevenness difference was obtained from the difference between the resin thickness (a) on the copper wiring and the resin thickness (b) at the portion without the copper wiring, and was evaluated based on the value having the largest unevenness.

  The results of each test are shown in Table 1 for the samples of Examples and Comparative Examples. It can be seen that the example samples are excellent in heat resistance (Tg) and mechanical strength (strength at break, elongation at break) and at the same time laminate properties. Moreover, the thermal expansion coefficient also shows a low value.

  The resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer of a multilayer printed wiring board.

It is a conceptual diagram which shows the uneven | corrugated difference of the insulating layer formed on the circuit board.

Claims (6)

(A) a polymer of a bismaleimide compound and a diamine compound, (B) an epoxy resin having two or more epoxy groups in one molecule, (C) a curing agent, and (D) a phenoxy resin and a polyvinyl acetal resin. 1 or more types of resin which contains the resin composition characterized by the above-mentioned. When the nonvolatile content of the resin composition is 100% by mass, the content of the component (A) is 10 to 50% by mass, the content of the component (B) is 15 to 45% by mass, and the content of the component (C) is The resin composition of Claim 1 whose content of 3-20 mass% and a component (D) is 10-50 mass%. An adhesive film in which the epoxy resin composition according to claim 1 or 2 is layered on a support film. The adhesive film with copper foil in which the resin composition of Claim 1 or 2 is layer-formed on copper foil. A prepreg in which the epoxy resin composition according to claim 1 or 2 is impregnated in a sheet-like reinforcing substrate made of fibers. The multilayer printed wiring board by which the insulating layer is formed with the hardened | cured material of the epoxy resin composition of Claim 1 or 2.

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