JP5200488B2 - Copper foil with resin for multilayer printed wiring board and multilayer printed wiring board produced using the same - Google Patents

Description

  The present invention relates to a copper foil with a resin for multilayer printed wiring boards and a multilayer printed wiring board, and more specifically, metal foil adhesion, heat resistance, moisture resistance, flame resistance, heat resistance with metal and dielectric properties (relative dielectric constant, The present invention relates to a copper foil with resin for multilayer printed wiring boards that is balanced in all of (dielectric loss tangent) and a multilayer printed wiring board manufactured using the same.

  In recent years, with the increase in the density of printed wiring boards, it has become common to provide via holes by laser light or plasma processing. However, when a prepreg containing an inorganic component such as glass fiber is used as an insulating layer, workability by laser light or plasma is poor, and therefore, only a resin containing no inorganic component is often used as an insulating layer. In this case, the thermosetting resin composition is applied to one side of the copper foil, the semi-cured resin-coated copper foil is laminated on the inner layer circuit board, and the outer layer copper foil is formed into a multilayer by forming a circuit and via holes. A printed wiring board is obtained.

  Thermosetting resins are widely used in fields that require high reliability, such as electronic parts, because their unique cross-linked structure exhibits high heat resistance and dimensional stability. In the interlayer insulating material, high copper foil adhesion for forming fine wiring and drilling workability are also required due to the recent demand for higher density. Moreover, due to recent environmental problems, mounting of electronic parts using lead-free solder and flame resistance using halogen-free are required, and therefore higher heat resistance and flame resistance than conventional ones are required. Furthermore, in order to improve the safety of the product and the working environment, there is a demand for a thermosetting resin composition that is composed only of low-toxic components and does not generate toxic gases.

  Melamine resins and guanamine compounds, which are thermosetting resins, are resins that are excellent in adhesiveness, flame retardancy, and heat resistance, but are poorly soluble in organic solvents and highly toxic N, N-dimethylformamide. Unless a nitrogen atom-containing organic solvent such as a large amount is used, it is difficult to produce a thermosetting resin composition, and storage stability is insufficient.

Many examples are known about the thermosetting resin using a melamine resin and a guanamine compound (for example, refer patent documents 1-5).
However, these thermosetting resins are those obtained by condensing melamine resins and guanamine compounds using aldehydes such as formaldehyde, and although the solubility in organic solvents has been improved, the thermal decomposition temperature is low, The required heat resistance to lead-free solder and heat resistance with copper are insufficient. Also, in fine processing and wiring formation, copper foil adhesion, flexibility, and toughness are insufficient, circuit patterns are broken or peeled off, and cracks occur when drilling or punching is performed. Such problems occur.

In addition, attempts have been made to introduce an imide skeleton that is thought to be useful for heat resistance and low dielectric constant. For example, a thermosetting composition for building-up using an aromatic diamine having an imide group and an epoxy resin is proposed. (See Patent Document 6). However, when a low molecular weight polyimide compound is used as a curing agent for an epoxy resin, most of the heat resistance and low dielectric properties as polyimide are not obtained, and the characteristics of the epoxy resin are often the same.
In general, polyimide resin is used in various industries as a polyimide film because of its heat resistance and dielectric characteristics, but most of it is a polyimide film, which is used for the production of copper foil with resin for multilayer printed wiring boards. It is difficult to use.

  On the other hand, phosphorus compounds have been proposed as halogen-free flame retardants to replace bromine-containing flame retardants. However, when using phosphoric acid or phosphoric acid ester, the amount of use is limited and sufficient flame retardancy cannot be obtained due to problems such as bleed, hydrolyzability, heat resistance and electrical reliability degradation. There's a problem. In addition, red phosphorus has problems such as safety reasons such as ignition due to impact and significant deterioration in reliability such as electric corrosion resistance.

Japanese Examined Patent Publication No. 62-46584 Japanese Patent Laid-Open No. 10-67942 JP 2001-11672 A Japanese Patent Laid-Open No. 02-258820 Japanese Patent Laid-Open No. 03-145476 JP 2000-17148 A

  In view of the current situation, the object of the present invention is a multilayer that can be easily molded and balanced in all of metal foil adhesion, heat resistance, moisture resistance, flame resistance, heat resistance with metal, dielectric constant and dielectric loss tangent. It is an object of the present invention to provide a resin-coated copper foil for printed wiring boards and a high-performance, high-density multilayer printed wiring board using the same.

  As a result of intensive studies to achieve the above object, the present inventors have blended a 6-substituted guanamine compound with a phenolic compound and an epoxy resin and uniformly dissolved in an organic solvent, and this resin composition. A resin composition which is a homogeneous solution obtained by adding a maleimide compound having an N-substituted maleimide group to a resin composition and reacting with a guanamine compound is suitable for the above-mentioned purpose, and is advantageous as a copper foil with a resin for multilayer printed wiring boards. It was found to be used in

That is, this invention provides the following copper foil with resin for multilayer printed wiring boards, and a multilayer printed wiring board.
1. A 6-substituted guanamine compound (a) represented by the following general formula (I) , a phenol resin (b) having a softening point of 120 ° C. or less, an epoxy resin (c) having at least two epoxy groups in one molecule, and organic It is obtained by applying a thermosetting resin composition containing a solvent (d), which is a uniform solution (referred to as “thermosetting resin composition A”), to one side of a copper foil and then forming a B stage. Copper foil with resin for multilayer printed wiring boards.

（式中、Ｒ₁はフェニル基、メチル基、ブチル基、アリル基、メトキシ基、ビニル基又はベンジルオキシ基を示す。）

(In the formula, R ₁ represents a phenyl group, a methyl group, a butyl group, an allyl group, a methoxy group, a vinyl group, or a benzyloxy group.)

2. It is obtained by further adding a maleimide compound (e) having at least two N-substituted maleimide groups in one molecule to the thermosetting resin composition in 1 and reacting with the 6-substituted guanamine compound (a). With a resin for multilayer printed wiring boards obtained by coating a single-sided copper foil with a thermosetting resin composition that is a uniform solution (referred to as “thermosetting resin composition B”) and then B-staged. Copper foil.
3. Copper with resin for multilayer printed wiring boards obtained by applying a composition obtained by adding a cresol novolac-type phenol resin as a curing agent to one side of a copper foil to the thermosetting resin composition in 1 or 2 above, and then forming a B-stage. Foil .
4 . The copper foil with resin for multilayer printed wiring boards according to any one of 1 to 3 , wherein the organic solvent (d) is a nitrogen-free organic solvent.
5 . The nitrogen-free organic solvent is an alcohol-based organic solvent (d1) or an alcohol-based organic solvent (d1), an ether-based organic solvent (d2), a ketone-based organic solvent (d3), or an aromatic-based organic solvent (d4). 4. The copper foil with resin for multilayer printed wiring boards as described in 4 above, which is an organic solvent containing at least one kind.
6 . 6. The copper foil with resin for multilayer printed wiring board as described in 5 above, wherein the nitrogen-free organic solvent is an organic solvent containing propylene glycol monomethyl ether or methyl cellosolve and at least one of methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.
7 . The multilayer printed wiring board produced using the copper foil with resin for multilayer printed wiring boards in any one of said 1-6 .

The resin-coated copper foil for multilayer printed wiring boards of the present invention can be easily molded, and is balanced in all of metal foil adhesion, heat resistance, moisture resistance, flame resistance, metal heat resistance, relative dielectric constant and low dielectric loss tangent. It is a good one.
Moreover, the thermosetting resin composition used for the copper foil with resin for multilayer printed wiring boards of the present invention reacts with the component (a) by adding a uniform solution of the components (a) to (d) or further adding the component (e). The above-mentioned excellent performance is obtained by using a homogeneous solution obtained without the use of a nitrogen-containing organic solvent such as highly toxic N, N-dimethylformamide and is excellent in safety and working environment. The copper foil with resin for multilayer printed wiring boards which has can be provided advantageously.

Hereinafter, the present invention will be described in detail.
First, the thermosetting resin composition A used for the resin-coated copper foil for the multilayer printed wiring board of the present invention is a 6-substituted guanamine compound (a), a phenolic compound (b) represented by the following general formula (I), It is a homogeneous solution containing an epoxy resin (c) having at least two epoxy groups in one molecule and an organic solvent (d).

（式中、Ｒ₁はフェニル基、メチル基、アリル基、ブチル基、メトキシ基、ビニル基又はベンジルオキシ基を示す。）

(In the formula, R ₁ represents a phenyl group, a methyl group, an allyl group, a butyl group, a methoxy group, a vinyl group, or a benzyloxy group.)

  Examples of the 6-substituted guanamine compound (hereinafter also referred to as 6-substituted guanamine compound (a)) represented by the general formula (I) of the component (a) include, for example, benzoguanamine (2,4-diamino-6-phenyl-s-triazine). ), Acetoguanamine (2,4-diamino-6-methyl-s-triazine), 2,4-diamino-6-vinyl-s-triazine, etc., among these, the reaction rate of the reaction is high, Benzoguanamine and 2,4-diamino-6-vinyl-s-triazine, which can have higher heat resistance, are more preferable, and benzoguanamine is particularly preferable from the viewpoint of low cost.

The phenolic compound (b) is a phenolic compound having one or more phenolic hydroxy groups in one molecule, and since the thermosetting resin composition A is a homogeneous solution, the phenolic resin is softened. Those having a point of 120 ° C. or lower are used.
Examples of the phenolic compound (b) include phenol, 2,4-dihydroxybenzoic acid, naphthol, (o-, m-, p-) cresol, bisphenol A and bisphenol F, and phenol having a softening point of 120 ° C or lower. Examples thereof include novolak resin, cresol novolak resin, bisphenol novolak resin, phenol aralkyl resin, triphenylmethane phenol resin, biphenylene phenol aralkyl resin, and naphthol aralkyl resin.
Among these, phenol novolac resin, cresol novolac resin and phenol aralkyl resin having a softening point of 120 ° C. or less are more preferable and cheaper because of their large effect of increasing the solubility of the guanamine compound, in terms of dielectric properties, heat resistance, and adhesiveness. A cresol novolac resin having a softening point of 120 ° C. or lower is particularly preferred from the viewpoint of excellent flame retardancy.

  The softening point referred to here is measured using the ring and ball method. Specifically, about 50 g of a sample is put in a mortar, finely pulverized, transferred to a 100 ml beaker, and melted on a sand bath. Place the shoulder ring, which has been heated to the same degree as the sample, on a metal plate and immediately pour the molten sample into the ring and let it cool at room temperature (0-30 ° C) for 30-40 minutes or with water 5 Cool for minutes. Excess sample is removed, a guard and a thermometer are attached, and the platform is immersed in a heating bath. Except for 3 minutes after the start of heating, it is heated at a heating rate of 3 to 5 ° C./min. The softening point is defined as the reading of the thermometer when the sample starts to soften and falls and touches the bottom plate.

In the thermosetting resin composition A, the amount ratio of the 6-substituted guanamine compound (a) and the phenolic compound (b) is such that the equivalent of the —NH ₂ group of the 6-substituted guanamine compound (a) and the phenolic compound The equivalent ratio of (b) to the hydroxy group equivalent is:
0.5 ≦ [-NH ₂ group equivalent] / [hydroxy group equivalent] ≦ 5.0
It is desirable that the amount be within the range shown in. By setting the corresponding amount ratio to 5.0 or less, the solubility in the organic solvent is not insufficient or gelation is not caused. By setting the ratio to 0.5 or more, the heat resistance of the thermosetting resin is lowered. There is nothing.

The epoxy resin (c) is not particularly limited as long as it is an epoxy resin having two or more epoxy groups in one molecule. For example, bisphenol A, bisphenol F, biphenyl, novolac, polyfunctional phenol And glycidyl ethers such as naphthalene series, alicyclic series and alcohol series, glycidyl amine series and glycidyl ester series, and the like.
Among these, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, bisphenol A novolak type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy from the viewpoint of dielectric properties, heat resistance, moisture resistance and metal foil adhesion Resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc. are preferable, and bisphenol F type epoxy resin, biphenyl aralkyl type epoxy resin, biphenyl type epoxy resin, phenol novolak type epoxy resin and the like from the viewpoint of flame retardancy and moldability A cresol novolac type epoxy resin is more preferable, and a phenol novolac type epoxy resin and a bisphenol F type epoxy resin are particularly preferable because they are inexpensive.

In the thermosetting resin composition A, an epoxy resin curing agent and a curing accelerator may be used.
Examples of curing agents for epoxy resins include acid anhydrides such as maleic anhydride and maleic anhydride copolymers, amine compounds such as dicyanodiamide, phenolic compounds such as phenol novolac, cresol novolac, and phenol aralkyl resins. . Of these, phenolic compounds such as phenol novolac, cresol novolak, and phenol aralkyl resins that have good heat resistance and dielectric properties are preferable, and are inexpensive and have improved flame retardancy and adhesion, so that cresol novolac type phenol resins Is particularly preferred.
Examples of epoxy resin curing accelerators include imidazoles and derivatives thereof, tertiary amines and quaternary ammonium salts.

In the thermosetting resin composition A, the content of the component (a) may be 1 to 98 parts by mass in 100 parts by mass of the total amount of the component (a), the component (b), and the component (c). Preferably, it is 10-89 mass parts, More preferably, it is 20-79 mass parts. Moreover, it is preferable that content of a component (b) shall be 1-50 mass parts, it is more preferable to set it as 1-30 mass parts, and it is especially preferable to set it as 1-25 mass parts. The content of the component (c) is preferably 1 to 98 parts by mass, more preferably 10 to 89 parts by mass, and particularly preferably 20 to 79 parts by mass. However, components (a) and (b) is preferably the equivalent of -NH ₂ group of the component (a), the hydroxy group equivalent of component (b) satisfy the equivalent ratio of the.
It is preferable to make content of a component (a) and a component (b) into a minimum value or more from a viewpoint of a flame retardance, adhesiveness, and a dielectric constant, and to make it into an upper limit or less from a heat resistant viewpoint. Moreover, it is preferable to make content of a component (c) into a minimum value or more from a viewpoint of a flame retardance, adhesiveness, and heat resistance, and to set it as an upper limit or less from a viewpoint of a dielectric constant.

In the thermosetting resin composition A, it is preferable to use a nitrogen-free organic solvent as the organic solvent (d).
That is, conventionally, nitrogen-containing organic solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like have been used as solvents for melamine resins and guanamine compounds. Therefore, it is not suitable for the purpose of the present invention, and it is preferable to use a nitrogen-free organic solvent.
Examples of the nitrogen-free organic solvent include alcohol-based organic solvents (d1) or alcohol-based organic solvents (d1), ether-based organic solvents (d2), ketone-based organic solvents (d3), and aromatic-based organic solvents (d4). Of these, an organic solvent containing at least one kind is preferable.
Examples of the alcohol-based organic solvent (d1) include ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether. Among these, butyl cellosolve and propylene glycol monomethyl ether are mentioned because of their solubility and low toxicity. More preferred is propylene glycol monomethyl ether, which is highly volatile and hardly remains as a residual solvent during the production of a prepreg.

In the thermosetting resin composition A, an organic solvent can be optionally contained together with the alcohol organic solvent (d1). Specifically, for example, an ether organic solvent (d2), a ketone organic solvent (d3) ) And an aromatic organic solvent (d4).
The ether organic solvent (d2) is tetrahydrofuran, etc. The ketone organic solvent (d3) is acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. The aromatic organic solvent (d4) is toluene, xylene, mesitylene, etc. Is mentioned. These organic solvents can be used alone or in combination of two or more.
In the organic solvents (d2) to (d4), methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone are preferable from the viewpoint of solubility and low toxicity, and methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like from the viewpoint of suppressing side reactions. More preferred is a ketone solvent, and methyl ethyl ketone, which is highly volatile and hardly remains as a residual solvent during the production of a prepreg, is particularly preferred.

  The amount of the organic solvent (d) used is preferably 10 to 1000 parts by mass, more preferably 100 to 500 parts by mass with respect to 100 parts by mass of the total amount of the components (a) to (c). It is especially preferable to set it as 200-500 mass parts. It is preferably 10 parts by mass or more from the viewpoint of solubility and 1000 parts by weight or less from the viewpoint of heat resistance.

The thermosetting resin composition A is a homogeneous solution containing a 6-substituted guanamine compound (a), a phenolic compound (b), an epoxy resin (c) and an organic solvent (d). By adding the phenolic compound (b) and the epoxy resin (c) to (a), the solubility of the guanamine compound (a) in the organic solvent can be improved, and a uniformly dissolved composition is obtained. It is done.
In order to melt | dissolve uniformly, it is preferable to heat at 20-130 degreeC, and it is more preferable to heat at 40-100 degreeC.

The thermosetting resin composition B used for the copper foil with resin for multilayer printed wiring boards of the present invention is a maleimide having at least two N-substituted maleimide groups in one molecule in addition to the thermosetting resin composition A. A homogeneous solution obtained by adding compound (e) [also referred to as N-substituted maleimide compound (e)] and reacting with 6-substituted guanamine compound (a).
In this reaction, the 6-substituted guanamine compound (a) is Michael-added to the N-substituted maleimide compound (e) to form a guanamine compound having an N-substituted maleimide group. The reaction product of the N-substituted maleimide compound (e) and the guanamine compound has a curing reactivity with the thermosetting resin. By using this reaction product for the thermosetting resin, a bismaleimide structure and a guanamine structure are obtained. A thermosetting resin having excellent dielectric properties, flame retardancy and heat resistance can be obtained.
Examples of the N-substituted maleimide compound (e) include bis (4-maleimidophenyl) methane, bis (4-maleimidophenyl) ether, bis (4-maleimidophenyl) sulfone, 3,3-dimethyl-5,5-diethyl- 4,4-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, m-phenylene bismaleimide, 2,2-bis (4- (4-maleimidophenoxy) phenyl) propane, and the like. Among them, bis (4-maleimidophenyl) methane, m-phenylenebismaleimide and bis (4-maleimidophenyl) sulfone, which have a high reaction rate and can have higher heat resistance, are preferable, and m-phenylenebismaleimide is preferable because it is inexpensive. And bis (4-maleimidophenyl) methane are more preferable. Bis from sexual point (4-maleimide phenyl) methane are particularly preferred.

The reaction temperature is preferably 70 to 200 ° C, more preferably 70 to 160 ° C. The reaction time is preferably 0.5 to 10 hours, more preferably 0.5 to 6 hours. In the reaction, it is preferable to add the N-substituted maleimide compound (e) little by little.
The amount of the N-substituted maleimide compound (e) used is such that the equivalent ratio of the equivalent of —NH ₂ group of the 6-substituted guanamine compound (a) to the equivalent of C═C group of the N-substituted maleimide compound (e) is 0.1 ≦ [total of C = C group equivalents] / [— NH ₂ group equivalents] ≦ 1.2
It is desirable that the amount be within the range shown in. By setting the corresponding ratio to be 0.1 or more, the solubility in an organic solvent is not insufficient, and by setting it to 1.2 or less, the adhesiveness and heat resistance of the thermosetting resin are not reduced.
In this reaction, a reaction catalyst can be optionally used as necessary. Examples of the reaction catalyst include amines such as triethylamine, pyridine, and tributylamine, imidazoles such as methylimidazole and phenylimidazole, and phosphorus-based catalysts such as triphenylphosphine. Can be used.

These thermosetting resin composition A and thermosetting resin composition B (hereinafter sometimes collectively referred to as “thermosetting resin composition”) may optionally contain an inorganic filler. it can. Examples of inorganic fillers include silica, mica, talc, short glass fiber or fine powder and hollow glass, antimony trioxide, calcium carbonate, quartz powder, aluminum hydroxide, magnesium hydroxide and the like. Silica, aluminum hydroxide and magnesium hydroxide are preferable from the viewpoint of dielectric properties, heat resistance and flame retardancy, and silica and aluminum hydroxide are more preferable from the viewpoint of low cost.
The content of the inorganic filler is the total amount of the components (a) to (d) (in the case of the thermosetting resin composition A) or the total amount of the components (a) to (e) (the thermosetting resin composition B). In the case of) 100 parts by mass, preferably 0 to 300 parts by mass, more preferably 20 to 200 parts by mass, and particularly preferably 20 to 150 parts by mass. When the content of the inorganic filler is 300 parts by mass or less, the moldability and adhesiveness are not lowered.

Furthermore, the thermosetting resin composition used for the resin-coated copper foil of the present invention is arbitrarily known thermoplastic resin, elastomer, flame retardant, to the extent that the thermosetting property as the resin composition is not impaired. An organic filler or the like can be contained.
Examples of the thermoplastic resin include polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, xylene resin, petroleum resin, silicone resin, and the like. .

Examples of the elastomer include polybutadiene , epoxy-modified polybutadiene, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and the like .

Examples of flame retardants include halogen-containing flame retardants containing bromine and chlorine, triphenyl phosphate, tricresyl phosphate, trisdichloropropyl phosphate, phosphazenes, red phosphorus and other phosphorus flame retardants, antimony trioxide, hydroxylation Examples include inorganic flame retardants such as aluminum and magnesium hydroxide. Among these flame retardants, phosphorus-based flame retardants that are non-halogen flame retardants, inorganic flame retardants, and the like are preferable from the viewpoint of the environment. In addition, it is particularly preferable to use a phosphorus-based flame retardant in combination with an inorganic flame retardant such as aluminum hydroxide from the viewpoint of compatibility with other characteristics such as flame retardancy and heat resistance.
Examples of the organic filler include organic powders such as silicone powder, polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, and polyphenylene ether.

  In addition, in the thermosetting resin composition used for the copper foil with resin of this invention, in order to make handling easy at the time of use, an organic solvent can be arbitrarily used as a dilution solvent. The organic solvent is not particularly limited. For example, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, alcohol solvents such as methyl cellosolve, ether solvents such as tetrahydrofuran, aromatic solvents such as toluene, xylene, and mesitylene. Examples of the solvent include one type or a mixture of two or more types.

  Furthermore, the thermosetting resin composition used for the resin-coated copper foil of the present invention optionally contains an ultraviolet absorber, an antioxidant, a photopolymerization initiator, a fluorescent whitening agent, an adhesion improver, and the like. For example, UV absorbers such as benzotriazoles, antioxidants such as hindered phenols and styrenated phenols, photopolymerization initiation of benzophenones, benzyl ketals, thioxanthones, etc. Agents, fluorescent brighteners such as stilbene derivatives, urea compounds such as urea silane, and adhesion improvers such as silane coupling agents.

  The copper foil with resin of the present invention is manufactured by applying the thermosetting resin composition, which is a uniform solution, to one side of the copper foil and then semi-curing (B-stage) by heating or the like. . In this production, those adjusted so that the gel time at 170 ° C. is 30 seconds to 120 seconds in the semi-cured state are preferable. By setting the gel time in the semi-cured state to 30 seconds or longer, the followability of the resin to the inner layer circuit is improved and no void is generated. On the other hand, when the gel time is 120 seconds or less, a large amount of resin flows out during pressing, and the accuracy of film thickness is not lost, and the pressing time is not very long, which is economically advantageous.

  The copper foil used when producing the resin-coated copper foil of the present invention includes YGP manufactured by Nippon Electrolytic Co., Ltd., JTC, JTC-AM, JTC-FM manufactured by Japan Energy, and GTS and GTS manufactured by Furukawa Circuit Foil. It is preferable to use a commercially available electrolytic copper foil such as -MP or F3-WS. More preferably, a copper foil having one surface or both surfaces previously roughened is good, and further, the surface is further processed with various metal platings, or those treated with a known coupling agent or organic chelating agent are suitable. It is. Moreover, it is preferable that the copper foil to be used has thickness of 9 micrometers or more and 18 micrometers or less. By using a copper foil having a thickness of 9 μm or more, the handling as a copper foil with a resin is good and it is not easily damaged during the operation. On the other hand, by using a copper foil having a thickness of 18 μm or less, the film thickness does not change due to the weight of copper during stacking, and from the viewpoint of producing a high-performance multilayer printed wiring board for intended use, A thick foil is disadvantageous for circuit formation.

  The film thickness of the thermosetting resin composition formed as described above is equal to or greater than the conductor thickness of the inner layer circuit board to be laminated, the remaining copper ratio of the inner layer circuit pattern, the plate thickness, the through hole diameter, and the surface via hole diameter. Although it varies depending on the set values of the number of holes and the insulating layer thickness, it is generally in the range of 10 to 120 μm. If the plate is thick and the resin filling volume of the through hole is large, a thicker film is required.

  As a form of the method for producing a multilayer printed wiring board using the resin-coated copper foil of the present invention, for example, the resin-coated copper foil of the present invention is hot-pressed on an inner layer circuit board on which a circuit is formed. , And then heat-cured as necessary, then drill holes with a drill or laser processing machine, plating the holes and conducting with the inner layer circuit, then etching the surface conductor For example, a configuration in which at least a pattern forming step is performed is suitably employed. At this time, the resin-coated copper foil of the present invention can be pressed through another prepreg or an adhesive sheet.

When manufacturing the multilayer printed wiring board of the present invention, first, a hole is made in the substrate obtained as described above using a semiconductor laser such as a CO ₂ laser, a UV-YAG laser, or a drill. When drilling with a CO ₂ laser in particular, it is necessary to etch the copper foil in the part where the hole is to be drilled first to provide a guide, or to treat the copper foil so that the laser light is sufficiently absorbed by the copper foil. become. In addition, the hole is either a through hole (through hole) for the purpose of conducting the front and back of the substrate, or a partial hole (belly via) for the purpose of conducting the circuit of the inner layer and the circuit of the adhesive film surface. Good. By performing copper plating and electrolytic copper plating, through holes, buried vias, or conformal vias are formed, and the copper foils on the front and back sides and the copper foil are electrically connected to the inner layer circuit.

Next, a desired multilayer printed wiring board is obtained by etching the surface copper foil to form a pattern by a known pattern etching method used in printed wiring boards. It is also possible to form a circuit using a pattern resist after etching the copper foil of the laminated resin-coated copper foil until it becomes thin for the purpose of making a fine pattern of the circuit. It is also possible to form a circuit by a semi-additive method.
The multilayer printed wiring board obtained in this way is further multilayered by repeating the above steps, or by layering by prepreg or copper foil and hot pressing using a hot plate press. Also good.

  As the inner layer substrate used in the above process, for example, a plastic substrate, a ceramic substrate, a metal substrate, a film substrate, or the like can be used. Specifically, a glass epoxy substrate, a glass polyimide substrate, an alumina substrate, or a low-temperature fired ceramic substrate. An aluminum nitride substrate, an aluminum substrate, a polyimide film substrate, or the like can be used. The inner layer circuit (wiring pattern) is preferably copper, and the copper circuit is preferably subjected to chemical surface treatment. On a circuit subjected to physical polishing such as buffing, the resin-coated copper foil of the present invention is not preferable because it has poor adhesion and tends to swell due to solder heat. As a suitable chemical treatment, a general-purpose blackening treatment or a treatment of forming a roughened surface by etching copper with a chemical, for example, Mec etch bond, Atotech bond film, McDermitt multi-bond, and the like are preferable.

Next, the present invention will be described in more detail with reference to the following examples, but these examples do not limit the present invention.
In addition, the copper foil with resin manufactured by the following each Example and each comparative example produced the sample with the following method, and measured and evaluated the performance.

(Sample 1: Copper foil sample with resin)
Two copper foils with resin produced in each example and each comparative example were laminated together so that the resin surface was inside, and heated at 120 ° C. under the condition of 0.49 MPa (5 kgf / cm ² ) for 30 minutes. Furthermore, it was heat-cured at 170 ° C. for 2 hours and integrally molded to prepare a copper foil sample with resin.
(Sample 2: Cured film)
The copper foil sample with resin of Sample 1 was etched to obtain a cured film for measuring physical properties.

(Sample 3: Laminated plate)
An inner layer circuit is formed from a glass-epoxy double-sided copper-clad laminate of 18 μm thick copper foil, and the resin surface of the resin-coated copper foil produced in each Example and each Comparative Example is formed on both surfaces of the MEC etch-bonded substrate. Stacked in contact with each other, using a hot plate press, cured at 0.49 MPa (5 kgf / cm ² ), 120 ° C., 20 minutes, then 2.45 MPa (25 kgf / cm ² ), 170 ° C., 2 hours, A laminate was prepared.

(Sample 4: multilayer printed wiring board)
In the laminated plate of Sample 3, a predetermined through hole portion is drilled with a drill, and a laser via portion is first provided with a guide by selectively removing the copper foil using an etching resist, and a laser processing machine. Drilled a hole. Next, after removing the smear of the through-hole part and the laser via part by desmear treatment, the hole part is made conductive by electroless copper plating and electrolytic copper plating, and a pattern is formed by etching through a commercially available etching resist, A multilayer printed wiring board was produced.

(Performance measurement / evaluation method)
(1) Glass transition temperature (Tg)
The cured film of Sample 2 was evaluated by observing the thermal expansion characteristics of the evaluation substrate using a TMA test apparatus (manufactured by DuPont, TMA2940).
(2) Measurement of linear expansion coefficient (CTEα1) The linear expansion coefficient (ppm / ° C.) of the copper foil sample with resin of Sample 1 was measured using a TMA test apparatus (manufactured by DuPont, TMA2940).
(3) Measurement of relative dielectric constant and dielectric loss tangent For the cured film of sample 2, the relative dielectric constant and dielectric loss tangent at a frequency of 1 GHz are measured according to JIS K6911 using a relative dielectric constant measuring apparatus (HP 4291B, manufactured by Hewllet Packerd). Was measured.

(4) Evaluation of hygroscopicity (water absorption rate) The cured film of Sample 2 was immersed in distilled water controlled at 23 ° C ± 2 ° C, and the water absorption rate was measured from the mass change after 24 hours.
(5) Evaluation of copper foil adhesion (copper foil peel strength) In accordance with JIS C6481, an evaluation board was prepared by immersing the laminate of Sample 3 in a copper etching solution, leaving a 1 cm wide strip and removing the copper foil. It manufactured and peel strength of the belt | band | zone part was measured using the autograph [Shimadzu Corporation AG-100C].

(6) Evaluation of solder heat resistance After the operation of immersing the multilayer printed wiring board (10 cm × 10 cm) of Sample 4 in a solder bath at 288 ° C. ± 3 ° C. for 10 seconds was repeated 5 times, peeling of the copper foil and the resin was confirmed. And evaluated as follows.
OK: no peeling, NG: peeling

(7) Evaluation of pattern formability About the multilayer printed wiring board of the sample 4, peeling of the circuit of 75 micrometers / 75 micrometers of line and space was visually inspected, and it evaluated as follows. It was.
OK: no peeling, NG: peeling (8) Evaluation of flame retardancy An insulating layer is formed on both sides of a 0.4 mm thick FR-4 base material with a cured coating to a thickness of 80 μm, and the test of UL94 Evaluation was made according to the method (Method V).

Production Example 1 [Production of Resin Composition (X-1)]
In a reaction vessel with a volume of 2 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a moisture meter with a reflux condenser, benzoguanamine: 31 parts by mass, cresol novolac resin [Dainippon Ink Chemical Co., Ltd., product Name: KA-1163, softening point 110 ° C.]: 15 parts by mass, phenol novolac type epoxy resin [manufactured by Dainippon Ink & Chemicals, Inc., trade name: N-770]: 54 parts by mass and propylene glycol monomethyl ether: 67 A mass part was added, the temperature was raised to 80 ° C., and the mixture was uniformly dissolved to produce a thermosetting resin composition [resin composition (X-1)].

Production Example 2 [Production of Resin Composition (X-2)]
In a reaction vessel with a volume of 2 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a moisture quantifier with a reflux condenser, benzoguanamine: 21 parts by mass, cresol novolac resin [Dainippon Ink Chemical Co., Ltd., product Name: KA-1163, softening point 110 ° C.]: 14 parts, phenol novolac type epoxy resin (manufactured by Dainippon Ink & Chemicals, Inc., trade name: N-770): 43 parts by mass and propylene glycol monomethyl ether: 67 parts by mass The portion was added and heated to 80 ° C. to dissolve uniformly. Next, 22 parts by mass of bis (4-maleimidophenyl) methane was added and reacted at 80 ° C. for 8 hours to produce a thermosetting resin composition [resin composition (X-2)].

Production Example 3 [Production of Resin Composition (X-3)]
In a reaction vessel with a volume of 2 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a moisture quantifier with a reflux condenser, benzoguanamine: 31 parts by mass, phenol aralkyl resin [Madewa Kasei Co., Ltd., trade name: MEH -7800H, softening point 85 ° C.]: 15 parts by mass, phenol novolac type epoxy resin (manufactured by Dainippon Ink & Chemicals, Inc., trade name: N-770): 54 parts and propylene glycol monomethyl ether: 67 parts by mass The mixture was heated to 80 ° C. and dissolved uniformly to produce a thermosetting resin composition [resin composition (X-3)].

Production Example 4 [Production of Resin Composition (X-4)]
In a reaction vessel with a volume of 2 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a moisture quantifier with a reflux condenser, benzoguanamine: 21 parts by mass, phenol aralkyl resin [Madewa Kasei Co., Ltd., trade name: MEH −7800H, softening point 85 ° C.]: 14 parts by mass, phenol novolac type epoxy resin (manufactured by Dainippon Ink & Chemicals, Inc., trade name: N-770): 43 parts by mass and propylene glycol monomethyl ether: 67 parts by mass The mixture was heated to 80 ° C. and dissolved uniformly. Next, 22 parts by mass of bis (4-maleimidophenyl) methane was added and reacted at 80 ° C. for 8 hours to produce a thermosetting resin composition [resin composition (X-4)].

Production Example 5 [Production of Resin Composition (X-5)]
In a reaction vessel with a volume of 2 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a moisture meter with a reflux condenser, benzoguanamine: 31 parts by mass, cresol novolac resin [Dainippon Ink Chemical Co., Ltd., product Name: KA-1163, softening point 110 ° C.]: 15 parts by mass, cresol novolac type epoxy resin [manufactured by Dainippon Ink & Chemicals, Inc., trade name: N-673]: 54 parts by mass and propylene glycol monomethyl ether: 67 A mass part was added, the temperature was raised to 80 ° C., and the mixture was uniformly dissolved to produce a thermosetting resin composition [resin composition (X-5)].

Production Example 6 [Production of Resin Composition (X-6)]
In a reaction vessel with a volume of 2 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a moisture meter with a reflux condenser, benzoguanamine: 31 parts by mass, 2-naphthol (manufactured by Kanto Chemical Co., Inc.): 15 parts by mass , Phenol novolac type epoxy resin [Dainippon Ink Chemical Co., Ltd., trade name: N-770]: 54 parts by mass and propylene glycol monomethyl ether: 67 parts by mass, heated to 80 ° C. and uniformly dissolved Then, a thermosetting resin composition [resin composition (X-6)] was produced.

Production Example 7 [Production of Resin Composition (X-7)]
In a reaction vessel with a volume of 2 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a moisture quantifier with a reflux condenser, benzoguanamine: 31 parts by mass, bisphenol F (manufactured by Mitsui Chemicals): 15 parts by mass, Phenol novolac type epoxy resin [Dainippon Ink Chemical Co., Ltd., trade name: N-770]: 54 parts by mass and propylene glycol monomethyl ether: 67 parts by mass were heated to 80 ° C. and dissolved uniformly. A thermosetting resin composition [resin composition (X-7)] was produced.

Examples 1-7, Comparative Examples 1-2
In Examples 1 to 7, the resin composition (X-1) to the resin composition (X-7) obtained in the above Production Examples 1 to 7, and in Comparative Example 1, a phenol novolac type epoxy resin [Dainippon Ink and Chemicals, Inc. (Product name: N-770), Comparative Example 2 uses a cresol novolac type epoxy resin [Dainippon Ink Chemicals, product name: N-673], and as an epoxy curing agent. Cresol novolac resin [Dainippon Ink Chemical Co., Ltd., trade name: KA-1165], fused silica as inorganic filler [Admatech Co., Ltd., trade name: SC2050-KC], flame retardant aluminum dialkylphosphinate Using salt (Clariant Co., Ltd., trade name: OP-930), blended in the proportions shown in Table 1, and using methyl ethyl ketone (MEK) as a diluent Te to obtain a resin content of 70% of the uniform coating varnish. Using a die coater, the obtained coating varnish was coated on a rough surface of copper foil having a thickness of 18 μm so that the film thickness of the dried coating film became 60 μm [Furukawa Circuit Foil Co., Ltd., trade name: F3-WS ] And dried at 40 to 120 ° C. to produce a copper foil with resin.
About the resin-coated copper foils obtained in each Example and each Comparative Example, the glass transition temperature (Tg), the linear expansion coefficient (CTEα1), the relative dielectric constant (1 GHz), the dielectric loss tangent (1 GHz) and the moisture absorption were obtained by the above-described methods. The copper foil adhesiveness (copper foil peel strength), solder heat resistance, pattern formability and flame retardancy were evaluated. The results are shown in Table 1.

As is apparent from Table 1, the resin-coated copper foils of the examples of the present invention have a glass transition temperature (Tg), a thermal expansion coefficient (CTEα1), a relative dielectric constant, a dielectric loss tangent, moisture resistance (water absorption rate), copper The balance of foil adhesion (copper foil peel strength), solder heat resistance, pattern formability, and flame retardancy is balanced.
On the other hand, the comparative example balances all of glass transition temperature (Tg), thermal expansion coefficient (CTEα1), relative dielectric constant, dielectric loss tangent, moisture resistance, copper foil adhesion, solder heat resistance, pattern formability and flame retardancy. There is nothing that can be removed, and it is inferior to any of the characteristics.
The copper foil with resin of the present invention and the multilayer printed wiring board using the same are excellent because the glass transition temperature (Tg) of the thermosetting resin composition is high and the coefficient of thermal expansion (CTEα1) of the copper foil with resin is small. Excellent heat resistance with metal because of the high copper foil peel strength of the laminate and sufficient metal foil adhesion to the conductor, and the multilayer printed wiring board has high solder heat resistance I understand that.
Further, the thermosetting resin composition used for the copper foil with resin of the present invention is excellent in relative dielectric constant, dielectric loss tangent, moisture resistance and flame resistance, and the multilayer printed wiring board of the present invention is also excellent in pattern moldability. ing.
As described above, the resin-coated copper foil of the present invention and the multilayer printed wiring board using the resin foil can be easily molded and have metal foil adhesion, heat resistance, moisture resistance, flame resistance, metal heat resistance, relative dielectric constant and All of the dielectric loss tangents are balanced, and are useful as printed wiring boards for electronic devices.

Claims (7)

A 6-substituted guanamine compound (a) represented by the following general formula (I), a phenol resin (b) having a softening point of 120 ° C. or less, an epoxy resin (c) having at least two epoxy groups in one molecule, and organic A copper foil with a resin for a multilayer printed wiring board obtained by applying a thermosetting resin composition containing a solvent (d), which is a uniform solution, to one side of a copper foil and then B-stage.

(In the formula, R ₁ represents a phenyl group, a methyl group, a butyl group, an allyl group, a methoxy group, a vinyl group, or a benzyloxy group.)   A maleimide compound (e) having at least two N-substituted maleimide groups in one molecule is further added to the thermosetting resin composition according to claim 1 and reacted with a 6-substituted guanamine compound (a). A copper foil with resin for multilayer printed wiring boards obtained by applying a thermosetting resin composition, which is a uniform solution, to one side of a copper foil and then B-stage. A resin for a multilayer printed wiring board obtained by applying a composition obtained by adding a cresol novolac type phenol resin as a curing agent to one side of a copper foil to the thermosetting resin composition according to claim 1 or 2 and then forming a B-stage. With copper foil . The copper foil with resin for multilayer printed wiring boards according to any one of claims 1 to 3, wherein the organic solvent (d) is a nitrogen-free organic solvent. The nitrogen-free organic solvent is an alcohol-based organic solvent (d1) or an alcohol-based organic solvent (d1), an ether-based organic solvent (d2), a ketone-based organic solvent (d3), or an aromatic-based organic solvent (d4). The copper foil with resin for multilayer printed wiring boards according to claim 4 , which is an organic solvent containing at least one kind. The resin-coated copper foil for multilayer printed wiring boards according to claim 5 , wherein the nitrogen-free organic solvent is an organic solvent containing propylene glycol monomethyl ether or methyl cellosolve and at least one of methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. . The multilayer printed wiring board produced using the copper foil with resin for multilayer printed wiring boards in any one of Claims 1-6 .