JP2002338887A - Insulating varnish using modified cyanate ester based resin composition and method for producing its resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulating varnish using a modified cyanate ester based curable resin composition which can realizes an insulating film having good heat resistance, moisture resistance, solvent resistance, and chemical resistance, suited in the build-up lamination system effective for rendering a printed-wiring board thinner/more lightweight and denser, having a low dielectric constant and a low dielectric loss tangent in the high frequency band region, and a low loss in a high-frequency circuit, and additionally, having good crack resistance and moldability such as circuit filling properties. SOLUTION: The insulating varnish is composed of a composition comprising (A) a cyanate ester compound, (B) a phenol compound, (C) a polyphenylene ether resin, (C) a filler, and (D) an epoxy resin as the essential components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified cyanate ester-based curable film used for forming an insulating layer in a printed wiring board, and to reduce the thickness of the printed wiring board by eliminating a substrate such as a glass cloth. Manufacture of heat-resistant insulating varnishes and films that can be reduced in weight and can easily form connection holes with an IVH (interstitial via hole) structure by a build-up lamination method, which is also effective in increasing the density of wiring About the method.

More specifically, a modified cyanate ester-based curable resin having excellent high-frequency characteristics, which is suitable for manufacture of printed wiring boards, such as wireless communication-related terminal equipment, antennas, and high-speed computers equipped with a microprocessor having a high clock frequency. The present invention relates to a method for producing an insulating varnish and a film comprising a composition.

[0003]

2. Description of the Related Art As electronic devices have become smaller and more sophisticated, there has been a demand for thinner, lighter, and higher-density substrate materials for printed wiring boards. In recent years, a build-up laminate type printed wiring board having an IVH structure, which has a small diameter and connects only necessary layers with non-through holes, has been developed and rapidly spread. The insulating layer of the build-up lamination type printed wiring board is made of a heat-resistant resin not containing a base material such as a glass cloth, and the hole for the IVH is made of photolithography using a photosensitive resin or a thermosetting resin. It is formed by a method such as thermal decomposition by a laser processing machine.

In recent years, the frequency of signals has been increasing in computers and information equipment terminals in order to process a large amount of data at a high speed. However, the higher the frequency, the greater the transmission loss of electric signals. There is a strong demand for the development of printed wiring boards that can handle high frequencies.

[0005] Transmission loss in a high-frequency circuit is greatly affected by dielectric loss determined by the dielectric properties of an insulating layer (dielectric) around the wiring, and the low dielectric constant and low dielectric constant of a printed wiring board substrate (especially insulating resin). Tangent (tan δ) is required. For example, in a device related to mobile communication, a substrate having a low dielectric loss tangent is strongly desired in order to reduce a transmission loss in a quasi-microwave band (1 to 3 GHz) with an increase in signal frequency.

Further, electronic information devices such as computers have been equipped with high-speed microprocessors whose operating frequency exceeds 1 GHz, and delay of high-speed pulse signals on printed wiring boards has become a problem. Since the signal delay time increases in the printed wiring board in proportion to the square root of the relative permittivity εr of the insulator around the wiring, a high-speed computer or the like requires a wiring board substrate having a low dielectric constant.

Furthermore, in these wiring boards, the insulation resin layer should not be broken or the wiring should be broken due to a temperature change in the manufacturing process or the use environment.

In the evaluation of this item, a temperature change like an accelerated test is forcibly applied to the test piece to observe the occurrence of cracks in the resin layer or to conduct a continuity test of a circuit formed on the processed test piece. is there.

[0009] In contrast to the above-mentioned technical trends of printed wiring boards, insulating materials having a low dielectric constant and a low dielectric loss tangent in a high frequency band, suitable for manufacturing the above-mentioned build-up laminated type printed wiring boards, and having excellent crack resistance. Film is needed.

Conventionally, a polyphenylene ether resin (PPO or PPE) resin of a heat-resistant thermoplastic resin (engineering plastics) has been known as a film material having good dielectric properties. However, an insulating material for a printed wiring board has been known. In order to apply this method, it was necessary to improve the heat resistance to withstand the solder connection step at the time of mounting and the solvent resistance and chemical resistance at other steps during the manufacture of the printed wiring board.

Therefore, as a method of improving heat resistance and solvent resistance, a method of modifying a polyphenylene ether resin with a thermosetting resin has been devised. For example, as a resin film using a cyanate ester resin having the lowest dielectric constant among thermosetting resins, a curable resin prepared by blending a cyanate ester resin with a polyphenylene ether resin as shown in JP-B-1-53700. There is a polyphenylene ether resin-based film using a resin composition. Similarly, as a resin composition using a cyanate ester-based modified resin, a resin composition of a bismaleimide / cyanate ester-modified resin and a polyphenylene ether resin disclosed in JP-B-63-33506 and
JP-A-311071 discloses a resin composition of a modified phenol resin / cyanate ester resin and a polyphenylene ether resin.

[0012] The polyphenylene ether resin, which is a thermoplastic resin, is provided with thermosetting properties to improve heat resistance and solvent resistance. Examples thereof include polyphenylene ether resins disclosed in Japanese Patent Publication No. 5-77705. Examples of the film include a film obtained by casting a resin composition of a crosslinkable polymer / monomer, and a film obtained by appropriately crosslinking a specific curable polyphenylene ether resin having an unsaturated group disclosed in JP-A-7-188362.

[0013]

[Problems to be Solved by the Invention]
The film made of a resin composition in which a cyanate ester resin is blended with a polyphenylene ether resin shown in Japanese Patent Application Publication No. Regarding the dielectric properties of the cured resin, although the dielectric constant is relatively better than the other compositions described below, the dielectric loss tangent tends to be higher than the value of the dielectric constant, and high frequency characteristics (particularly, reduction of transmission loss) Was insufficient.

JP-B-63-33506 and JP-A-5-33506
The method disclosed in Japanese Patent No. 311071 discloses that a thermosetting resin that modifies a polyphenylene ether resin is a bismaleimide / cyanate ester-modified resin or a modified phenol resin /
Because it is a cyanate ester resin, although the compatibility with polyphenylene ether resin is slightly better,
The dielectric property of the cured resin is lower than that of the resin modified with the cyanate resin alone because it contains other thermosetting resins other than the cyanate ester resin. As a result, the high-frequency properties are further insufficient. there were.

In the method disclosed in Japanese Patent Publication No. 5-77705, a cross-linkable polymer such as polytriallyl isocyanurate and styrene-butadiene copolymer and a cross-linkable monomer such as triallyl isocyanurate are blended into a polyphenylene ether resin. Thermosetting (radical polymerizable)
However, since the crosslinkable polymer and monomer are highly polar compounds, there has been a problem that the dielectric properties of the cured resin are deteriorated by the unreacted small components remaining.

The method disclosed in Japanese Patent Application Laid-Open No. Hei 7-188362 uses a polymer in which an unsaturated group such as an allyl group is introduced into the polyphenylene ether itself. In addition to the fact that the derivative is the main component, the melt viscosity is originally high, and because the radical polymerization of unsaturated groups is used, the curing proceeds at once in a chain reaction, so the minimum melt viscosity during curing is high and It has the property that the rate of increase in melt viscosity is large, and as a result of insufficient fluidization of the resin during press molding, voids are generated and the circuit filling properties become insufficient, and the control range of the pressing conditions in the multilayer bonding process However, there has been a problem that the moldability is poor, such as narrowing.

In view of such a situation, the present inventors have previously proposed a method of using a composition obtained by modifying a specific cyanate ester resin with a monohydric phenol compound as a resin composition for a printed wiring board (Japanese Patent Application No. Hei. No. -80033). According to this method, a specific cyanate ester resin can be modified with a monohydric phenol compound to obtain a resin composition having a low dielectric property in a high frequency (GHz) band, particularly a low dielectric loss tangent. There is a problem that a specific cyanate ester resin is special and expensive.

The present invention provides an insulating film suitable for a build-up lamination method which has good heat resistance, moisture resistance, solvent resistance, and chemical resistance, and is effective for reducing the thickness, weight, and density of a printed wiring board. A modified cyanate ester-based curable resin composition that has a low dielectric constant and a low dielectric loss tangent in a high frequency band, can realize low loss of a high frequency circuit, and has good moldability such as crack resistance and circuit filling property. It is intended to provide a method for producing an insulating varnish and a film used.

[0019]

SUMMARY OF THE INVENTION The present invention relates to the following items. (1) (A) a cyanate ester compound, (B) a phenol compound, (C) a polyphenylene ether resin,
(D) An insulating varnish comprising a resin composition containing a filler as an essential component. (2) (A) a cyanate ester compound, (B) a phenol compound, (C) a polyphenylene ether resin,
An insulating varnish comprising a resin composition containing (D) a filler and (E) an epoxy resin as essential components. (3) The insulating varnish according to any one of (1) and (2), wherein a filler made of an elastic body containing silicon is used as the filler. (4) The insulating varnish according to any one of claims 1 and 2, wherein (D) a filler made of an elastic material containing an organic substance is used as the filler. (5) The insulating varnish according to any one of claims 1 and 2, wherein (D) a filler containing 60% by weight or more of polybutadiene is used. (6) The insulating varnish according to any one of (1) to (5), wherein (A) is a cyanate ester compound represented by the formula [1].

[0020]

Embedded image (7) The insulating varnish according to any one of (1) to (6), wherein (B) is a monohydric phenol compound represented by the formula [2].

[0021]

Embedded image (Wherein, R ₄ and R ₅ represent a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms, and may be the same or different, and n is a positive integer of 1 to 2). 8) The insulating varnish according to any one of (1) to (7), wherein 4 to 30 parts by weight of the (B) phenolic compound is blended with respect to 100 parts by weight of the (A) cyanate ester compound. (9) The insulating varnish according to any one of (1) to (8), which comprises a modified cyanate ester resin obtained by reacting (A) a cyanate ester compound with (B) a phenol compound. (10) (A) As a cyanate ester compound,
Insulation according to any one of (1) to (9), which has 2,2-bis (4-cyanatophenyl) propane or 2,2-bis (3,5-dimethyl-4-cyanatophenyl) methane. varnish. (11) As the phenolic compound (B), p- (α
-Cumyl) The insulating varnish according to any one of (1) to (10), which contains phenol. (12) (C) The polyphenylene ether resin is an alloyed polymer of poly (2,6-dimethyl-1,4-phenylene) ether and polystyrene or styrene-butadiene copolymer, 1,
The insulating varnish according to any one of (1) to (11), which is a polymer containing 50% or more of 4-phenylene) ether. (13) The insulating varnish according to any one of (1) to (12), further including a metal-based reaction catalyst in the resin composition. (14) The metal-based reaction catalyst is manganese, iron, cobalt,
(13) The insulating varnish according to (13), which is one or more selected from 2-ethylhexanoate, naphthenate, and acetylacetone complex of nickel, copper, and zinc. (15) A resin film obtained by semi-curing or curing the insulating varnish according to any one of (1) to (14). (16) A method of manufacturing a multilayer printed wiring board in which, after laminating the resin film described in (15) on a wiring board on which a circuit has been formed, a circuit on an outer layer surface is formed and the circuit is electrically connected to an inner layer circuit. (17) A resin film with a metal foil obtained by applying the insulating varnish according to any one of (1) to (14) on a metal foil and semi-curing or curing. (18) A method of manufacturing a multilayer printed wiring board in which, after laminating the resin film with a metal foil described in (17) on a wiring board on which a circuit has been formed, a circuit on an outer layer surface is formed and the circuit is electrically connected to the inner layer circuit. . (19) The insulating varnish according to any one of (1) to (14) is applied to a circuit board on which a circuit has been formed, the solvent is removed by heating and drying, and a film is formed and cured to form a circuit on the outer layer surface. A method of manufacturing a multilayer printed wiring board for making electrical conduction with an inner layer circuit. (20) An insulating layer using the insulating varnish according to any one of (1) to (14) is provided on a circuit board on which a circuit has been formed, and a circuit on an outer layer surface is further formed on the insulating layer.
A multilayer printed wiring board with conduction between the inner layer circuit and the outer layer circuit.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The modified cyanate ester resin composition of the present invention comprises (A) a cyanate ester compound,
Essential components are (B) a phenolic compound, (C) a polyphenylene ether resin, and (D) a filler.

As the cyanate ester compound (A) in the present invention, a cyanate ester compound having two cyanato groups in one molecule represented by the formula [1] can be used. Examples of the compound represented by the formula [1] include bis (4-cyanatophenyl) ethane,
2,2-bis (4-cyanatophenyl) propane, 2,
2-bis (3,5-dimethyl-4-cyanatophenyl)
Methane, 2,2-bis (4-cyanatophenyl) -1,
1,1,3,3,3-hexafluoropropane, α,
α'-bis (4-cyanatophenyl) -m-diisopropylbenzene, cyanate esterified phenol-added dicyclopentadiene polymer and the like. Among them, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-dimethyl-4-cyanatophenyl) methane, and the like particularly have a balance between the dielectric properties of the cured product and the curability. It is preferable because it is good. As the cyanate ester compound (A), one type may be used alone, or two or more types may be used in combination.

As the phenol compound (B) in the present invention, a monovalent phenol compound is preferably used, and for example, a phenol compound represented by the formula [2] can be used. Compounds having good heat resistance are preferred. As the compound represented by the formula [2], for example, p-
(Α-cumyl) phenol. (B)
One kind of phenolic compound may be used alone,
Two or more kinds may be used as a mixture.

In the present invention, the compounding amount of the (B) phenol compound is (A) the cyanate ester compound 100
The amount is preferably 2 to 40 parts by weight to 5 parts by weight.
The amount is more preferably from 30 to 30 parts by weight, and particularly preferably from 5 to 25 parts by weight. If the amount of the phenolic compound (B) is less than 2 parts by weight, sufficient dielectric properties cannot be obtained, and the dielectric loss tangent in a high-frequency band tends to be insufficient. If it exceeds 40 parts by weight, the dielectric loss tangent tends to be rather high, which is not desirable. Therefore, in order to obtain a modified cyanate ester-based resin film having a low dielectric loss tangent in the high frequency band provided by the present invention, it is necessary to use (B) a phenolic compound in an appropriate amount relative to (A) a cyanate ester compound. There is.

The (A) cyanate ester compound and (B) phenol compound in the present invention are generally used as a modified cyanate ester resin obtained by reacting each. That is, it is used as an imide carbonate-modified resin obtained by adding (A) a cyanate ester compound to a (B) phenol compound together with a prepolymer of the cyanate ester compound.

When reacting the (A) cyanate ester compound with the (B) phenol compound, the (B)
A phenolic compound may be used as a modified cyanate ester resin by introducing all of the above-mentioned proper compounding amount from the initial stage of the reaction and reacting it. B) A phenol compound may be added. When the remaining (B) phenolic compound is introduced after cooling, the remaining reaction proceeds during the B-stage or at the time of curing. The reaction is carried out at temperatures between 40 and 140
Proceed under the condition of ° C.

As the polyphenylene ether resin (C) in the present invention, for example, poly (2,6-dimethyl-
Alloyed polymer of 1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene) ether and polystyrene, poly (2,6-dimethyl-1,4-phenylene) ether and styrene-butadiene copolymer And an alloyed polymer of poly (2,6-dimethyl-1,4-phenylene) ether and polystyrene, and poly (2,6-dimethyl-1,4-phenylene). Alloyed polymers of ether and styrene-butadiene copolymer are preferred. (C)
It is preferable to use a polymer in which the component amount of poly (2,6-dimethyl-1,4-phenylene) ether in the polyphenylene ether resin is 50% by weight or more because the cured product has good dielectric properties. It is particularly preferred that the polymer contains 65% by weight or more.

The amount of the polyphenylene ether resin (C) in the present invention is preferably 5 to 500 parts by weight, more preferably 10 to 300 parts by weight, based on 100 parts by weight of the cyanate ester compound (A). More preferably, it is particularly preferably 10 to 200 parts by weight.
If the compounding amount of the (C) polyphenylene ether resin is less than 5 parts by weight, sufficient dielectric properties tend not to be obtained,
If the amount exceeds 500 parts by weight, the reactivity of the cyanate ester resin (A), which is a thermosetting component, is reduced due to the diluting effect of the (C) polyphenylene ether resin, and the heat resistance and solvent resistance of the obtained resin film may be deteriorated. There is.

The resin composition of the present invention preferably contains a metal-based reaction catalyst which promotes the reaction between (A) the cyanate ester compound and (B) the phenol compound. The metal-based reaction catalyst is used as a reaction catalyst when producing the modified cyanate-based resin composition and a curing accelerator when the resin film is cured. As the metal-based reaction catalyst, a catalyst containing manganese, iron, cobalt, nickel, copper, zinc or the like is used. Specifically, an organic metal salt compound such as 2-ethylhexanoate or naphthenate of the metal is used. Alternatively, it is used as an organometallic complex such as an acetylacetone complex. The same metal-based reaction catalyst may be used alone in the reaction accelerator for producing the modified cyanate-based resin composition and the curing accelerator for producing the laminate, or using two or more different types each. Is also good.

The filler (D) of the present invention is an electrically insulating filler. Examples of the filler include an elastic body containing silicon (eg, silicone rubber powder), an elastic body made of an organic material, For example, polybutadiene rubber,
An elastic body made of poly (acrylate ester) rubber or an elastic body containing at least 60% by weight of a rubber layer (for example, polybutadiene rubber, poly (acrylate ester) rubber, etc.);
Alternatively, at least one kind of core-shell rubber having a rubber layer (same as above) as a core and another elastic body as a shell layer can be used.

The average particle size of the filler is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less. By setting the average particle diameter to 10 μm or less, it is easy to prevent a decrease in insulating properties between insulating layers and between wirings, and it is possible to cope with fine wiring with thinner insulating layers.

The amount of the filler is 100
1 to 300 parts by weight, preferably 3 to 2 parts by weight, per part by weight
00 parts by weight is more preferred. If the amount exceeds 300 parts by weight, the filling property of the inner layer circuit by the insulating layer tends to decrease. If the amount is less than 1 part by weight, the effect of blending the filler is not sufficiently obtained.

The filler may form a functional group (eg, an epoxy group) which reacts with a resin other than the filler on the surface of the filler by treatment with a coupling agent or the like. Thereby, the compatibility and adhesion of the filler with the matrix resin may be improved, and the effect of addition may be improved.

After preparing an insulating varnish in order to improve the dispersibility when mixing the filler, a grinder is used.
The kneading with a roll mill or a bead mill can be performed in combination. After kneading, it is preferable to remove bubbles in the varnish by defoaming under reduced pressure or the like.

As the epoxy resin (E) of the present invention, for example, dicyclopentadiene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin Resin, bisphenol A novolak type epoxy resin,
Salicylaldehyde novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin,
Examples include isocyanurate-type epoxy resins, aliphatic cyclic epoxy resins, and halides, hydrogenated products thereof, and one or two or more kinds of mixtures of the above-mentioned resins. Examples of the alicyclic epoxy resin include a dicyclopentadiene type epoxy resin. Among them, dicyclopentadiene type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol A type epoxy resin, etc. have excellent symmetry of molecular skeleton and can obtain resin having more excellent dielectric properties. It is preferable because it can be performed.

In the present invention, the amount of the epoxy resin (E) is preferably 10 to 600 parts by weight based on 100 parts by weight of the cyanate ester compound (A).
More preferably, the amount is from 0 to 500 parts by weight. If the amount of the epoxy resin (E) is less than 30 parts by weight, the moisture resistance tends not to be sufficiently improved, and if it exceeds 600 parts by weight, the dielectric properties, particularly the dielectric loss tangent, tend to increase. Further, the compounding time of the epoxy resin (E) in the present invention may be simultaneously and collectively added when producing the modified cyanate resin composition, or after the modification reaction is completed when producing the modified cyanate resin composition. You may add and mix. In particular, when added after the completion of the modification reaction, excellent dielectric properties tend to be obtained.

The amount of the metal-based reaction catalyst in the present invention is preferably 1 ppm to 300 ppm in terms of the weight ratio to the cyanate ester compound (A).
More preferably, it is 1 ppm to 200 ppm. If the amount of the metal-based reaction catalyst is less than 1 ppm, the reactivity and curability tend to be insufficient. If the amount exceeds 300 ppm, the control of the reaction becomes difficult, and the curing becomes too fast, resulting in poor fluidity and moldability. Tend to be worse. In addition, the compounding time of the metal-based reaction catalyst in the present invention, the amount required as a reaction accelerator and a curing accelerator in the production of the resin composition may be simultaneously compounded together, or modified cyanate-based resin composition May be used in an amount necessary for accelerating the modification reaction, and after completion of the reaction, the remaining catalyst or another metal-based catalyst may be added and mixed as a curing accelerator.

The composition used in the curable resin film of the present invention may optionally contain a flame retardant, an inorganic filler, a curing accelerator and other additives. Examples of flame retardants include brominated phenols such as tribromophenol and tetrabromobisphenol A, brominated epoxy resins such as tetrabromobisphenol A type epoxy resin and brominated novolak type epoxy resin, brominated polystyrene and brominated Brominated thermoplastic resin such as polycarbonate, polybromodiphenyl ether represented by decabromodiphenyl ether, 1,2-dibromo-4
-Brominated hydrocarbons such as-(1,2-dibromoethyl) cyclohexane, tetrabromocyclohexane and hexabromocyclododecane; bromine such as 2,4,6-tris (tribromophenoxy) -1,3,5-triazine Triphenyl cyanurate-based flame retardants and the like.
Among them, 1,2-dibromo-4- (1,2-dibromoethyl) cyclohexane, tetrabromocyclooctane, hexabromocyclododecane and 2,4,6-tris (tribromophenoxy) -1,3,5- Flame retardants such as triazines have good dielectric properties of the cured product obtained because they have no reactivity with cyanate ester compounds,
preferable.

In the present invention, the compounding amount of the flame retardant is (A)
Total amount of cyanate ester compound, (B) phenol compound and (C) polyphenylene ether resin 100
The amount is preferably 5 to 200 parts by weight, more preferably 5 to 150 parts by weight, based on 10 parts by weight.
It is particularly preferred that the amount be from 100 to 100 parts by weight. If the amount of the flame retardant is less than 5 parts by weight, the flame resistance tends to be insufficient, and if it exceeds 200 parts by weight, the heat resistance of the resin tends to decrease.

As the inorganic filler, silica, alumina,
Aluminum hydroxide, calcium carbonate, clay, talc, silicon nitride, boron nitride, titanium oxide, barium titanate, lead titanate, strontium titanate and the like can be used. The amount is preferably not more than 300 parts by weight based on 100 parts by weight of the total amount of the resin composition of the present invention in order to obtain a uniform and good handleability of the resin film.

When the resin is an epoxy resin, an imidazole compound, an organic phosphorus compound, a tertiary amine, a quaternary ammonium salt, or the like is used as the curing accelerator. The ratio of this curing accelerator to the resin is as follows:
The range is preferably 0.01 to 25 parts by weight, more preferably 0.01 to 20 parts by weight, based on 0 parts by weight. When the amount of the curing accelerator is 0.01 part by weight or less, the accelerating action tends not to be exhibited. When the amount exceeds 25 parts by weight, the control of the reaction becomes difficult, or the curing becomes too fast, the fluidity becomes poor, and the moldability becomes poor. Tends to be worse

To produce the curable film of the present invention,
The resin composition described above is dissolved in a solvent to form a varnish of 10 to 70% by weight of the active ingredient. The varnish is applied to one surface of a carrier film using a bar coater or a roll coater, and then the solvent is removed by heating and drying to form a film. (Film formation).

Specific examples of the solvent used in the production of the above resin varnish include aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as trichloroethylene and chlorobenzene, and N, N-dimethyl. Amide-based solvents such as formamide and N, N-dimethylacetamide and nitrogen-based solvents such as N-methylpyrrolidone are used. Particularly, aromatic hydrocarbons such as benzene, toluene and xylene are more preferable. These solvents may be used alone or as a mixture of two or more. The compounding amount of the aromatic hydrocarbon solvent is preferably 25 to 900 parts by weight, more preferably 40 to 600 parts by weight, and more preferably 60 to 4 parts by weight based on 100 parts by weight of the total amount of the resin composition.
00 parts by weight is particularly preferred.

When ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone are used in combination with an aromatic hydrocarbon solvent, the varnish becomes a suspension solution, but the advantage is that a higher concentration solution can be obtained. There is. However, if the amount of the ketone is too large, the resin composition may separate and settle. Therefore, the amount of the ketone solvent is 2 parts by weight per 100 parts by weight of the aromatic hydrocarbon solvent.
It is preferably at most 50 parts by weight.

As the carrier film used in the present invention, a metal foil such as copper or aluminum, a resin film such as polyester or polyimide, or a film obtained by applying a release agent to the surface of these carrier films can be used. A resin film with a metal foil such as a resin film with a copper foil using a copper foil as a carrier film has an advantage that the metal foil can be used as a circuit conductor as it is,
It is preferable to apply a release agent treatment to the carrier film in order to improve the workability when peeling off the curable film from the carrier film or peeling off only the carrier film after laminating the film with carrier on the substrate.

The curable film having the insulating resin layer formed on one side of the carrier film as described above can be used for manufacturing a printed wiring board as described below. For example,
One or a plurality of sheet-like resins from which the carrier film has been removed are laminated, and copper foil is placed above and below them and press-molded, or a film coated on the copper foil is bonded so that the resin layers are combined, and further, If necessary, a copper-clad laminate for a printed wiring board can be manufactured by interposing one or more sheet-like resins from which a carrier film has been removed and press-molding them. The pressing conditions are not particularly limited, and generally used conditions can be applied. Usually, the pressing conditions are 150 to 250 ° C., the pressure is 0.1 to 5 MPa, and the time is 0.5 to 1 hour.

Further, after forming a circuit on a conventional copper-clad laminate of a glass cloth base material or the above-described copper-clad laminate, one or more sheet-like resins from which a carrier film has been removed are laminated, and a copper is further laminated thereon. A substrate for a multilayer wiring board can be manufactured by arranging a foil and press-forming or arranging a film coated on a copper foil and press-forming.

Also, after forming a circuit on a conventional copper-clad laminate of a glass cloth base material or the above-described copper-clad laminate, apply an insulating varnish, heat and dry, place a copper foil thereon, and press-mold. Alternatively, a substrate for a multilayer wiring board can be manufactured by arranging a film coated on a copper foil and press-forming or plating.

Note that a conventional method can be applied to the formation of the circuit described above. For example, a perforated or non-perforated hole is formed in the copper clad laminate or the multilayer wiring board substrate as necessary, and then the inner wall of the hole is made conductive by electroless plating or electroplating as necessary. A circuit can be formed by processes such as protection of the substrate, formation of an etching resist, and removal of copper in a non-wiring portion by etching.

Further, in the curable film of the present invention, drilling and laser processing can be employed as a method for drilling through or non-through holes. In the case of laser processing, laser drilling is possible by a direct imaging method of forming a hole directly by laser shot or a conformal mask method using a metal mask, etc., but the curable film shown in the present invention In a case where a copper foil as an example is used as a carrier film, laser drilling can be performed using a copper foil as a mask in which a place where a through or non-through hole is to be formed is removed by etching.

[0052]

The present invention will be described in more detail with reference to the following examples. Varnishes for curable films were produced according to the amounts shown in Table 1, and semi-cured resin films were produced.

(Preparation of Base Varnish 1) 300 g of toluene and 70 g of polyphenylene ether resin (Nonyl PKN4752, trade name of Nippon GE Plastics Co., Ltd.) were placed in a four-neck separable flask equipped with a thermometer, a cooling tube, and a stirrer. And heated to 80 ° C. to dissolve with stirring. Next, 2,2-bis (4-cyanatephenyl) propane (ArocyB-10, trade name, manufactured by Asahi Ciba Co., Ltd.)
150 g and 10 g of p- (α-cumyl) phenol (manufactured by Sun Techno Chemical Co., Ltd.) were added and dissolved, and then a 10% toluene diluted solution of manganese naphthenate (Mn content = 6% by weight, manufactured by Nippon Chemical Industry Co., Ltd.) was added. 15 g was added and reacted at the reflux temperature for 3 hours. After this, cool down to room temperature,
After adding and dissolving 8 g of p- (α-cumyl) phenol (manufactured by Sun Techno Chemical Co., Ltd.), the mixture was stirred for 1 hour to prepare a resin varnish for a curable film (solid content concentration: 44% by weight).

(Preparation of Base Varnish 2) 400 g of toluene and 70 g of polyphenylene ether resin (Nonyl PKN4752, trade name of Nippon GE Plastics Co., Ltd.) were placed in a four-neck separable flask equipped with a thermometer, a cooling tube and a stirrer. And heated to 80 ° C. to dissolve with stirring. Next, 2,2-bis (4-cyanatephenyl) propane (ArocyB-10, trade name, manufactured by Asahi Ciba Co., Ltd.)
100 g and 12 g of p- (α-cumyl) phenol (manufactured by San Techno Chemical Co., Ltd.) were added and dissolved, and then a 10% toluene diluted solution of manganese naphthenate (Mn content = 6% by weight, manufactured by Nippon Chemical Industry Co., Ltd.) was added. 3 g was added and reacted at reflux temperature for 5 hours. Thereafter, the mixture is cooled to room temperature and a dicyclopentadiene type epoxy resin (HP-72000)
L, 60 g of Dainippon Ink Co., Ltd., 170 g of brominated epoxy resin (ESB400T, manufactured by Sumitomo Chemical Co., Ltd.), imidazole-based curing accelerator (Curesol 2)
After adding 2 g of MZ-CNS (manufactured by Shikoku Chemicals) and 200 g of toluene and stirring for 1 hour, a resin varnish for a curable film (solid content concentration: about 40% by weight) was produced.

(Example 1) Silicone rubber powder (Trefil E-601, manufactured by Dow Corning Toray Silicone Co., Ltd.) was added to the above base varnish 1 so as to be 10 parts by weight based on 100 parts by weight of the solid content of the base varnish. And stirred and mixed for 1 hour.

(Example 2) Silicone rubber powder (Trefil E-601, manufactured by Dow Corning Toray Silicone Co., Ltd.) was added to the base varnish 2 in an amount of 20 parts by weight based on 100 parts by weight of the solid content of the base varnish. And stirred and mixed for 1 hour.

(Example 3) A polybutadiene-based core-shell rubber (Kureha paraloid EXL2)
655, manufactured by Kureha Chemical Industry Co., Ltd.) was added in an amount of 10 parts by weight based on 100 parts by weight of the solid content of the base varnish, followed by stirring and mixing for 1 hour.

Example 4 A polybutadiene-based core-shell rubber (Kureha paraloid EXL2) was added to the base varnish 2 described above.
655, manufactured by Kureha Chemical Industry Co., Ltd.) was added in an amount of 10 parts by weight based on 100 parts by weight of the solid content of the base varnish, followed by stirring and mixing for 1 hour.

The varnishes shown in Examples 1 to 4 were dispersed with stirring using a bead mill as necessary.

The varnishes of Examples 1 to 4 were coated with a 50 μm-thick polyethylene terephthalate (PET) film (Purex A-63, using a comma coater (manufactured by Hirano Techseed Co., Ltd.)) as a bar coater.
Coating and drying (trade name, manufactured by Teijin Limited) (150 ° C./1 minute) were performed to prepare a resin film with a carrier film having a resin layer thickness of 30 to 33 μm. The resin film obtained was excellent in handleability without resin cracking or powder dropping even when cut with a cutter knife.

(Comparative Example 1) A varnish was prepared in the same manner as in the preparation of the base varnish 1, and this varnish was used as a comma coater (a type of bar coater, manufactured by Hirano Techseed Co., Ltd.).
Using a polyethylene terephthalate (PET) film (Purex A-6) with a release agent having a thickness of 50 μm
3, Teijin Co., Ltd.) Coating and drying (150 ℃ /
(1 minute) to prepare a resin film with a carrier film having a resin layer thickness of 30 to 33 μm. Even if the obtained resin film is cut with a cutter knife, there is no resin cracking or powder drop,
Excellent handleability.

[0062]

[Table 1] (A) B-10, trade name, manufactured by Asahi Ciba Co., Ltd. (B) PCP, trade name, manufactured by San Techno Chemical Co., Ltd. (C) PPO nonyl PKN4752, trade name, manufactured by Japan GE Plastics Co., Ltd. (D) T; E-601 (Trade name, manufactured by Toray Dow Silicone Co., Ltd.) K; EXL2655 (trade name, manufactured by Kureha Chemical Industry Co., Ltd.) (E) H; HP-7200L (trade name, manufactured by Nippon Ink Co., Ltd.) Product name of Chemical Industry Co., Ltd.)

Next, with respect to the resin films with a carrier film of Examples 1 to 4 and Comparative Example 1, the resin film was peeled off from the carrier film, and 12 of them were stacked on top and bottom using the mirror surface of the electrolytic copper foil as a peeling surface. , 200 ° C, 1.5
Pressing was performed at 1 MPa for 1 hour to produce each resin molded film having a thickness of about 400 μm.

The cured products of the resin molded films of Examples 1 to 4 and Comparative Example 1 were evaluated for dielectric properties in the GHz band, glass transition temperature, and tensile modulus.

The resin cured product from which all of the copper foil was removed by chemical etching was measured for dielectric constant and dielectric loss tangent at 1 GHz using an RF impedance / material analyzer (HP 4291B, manufactured by Agilent Technologies). In addition, a test piece was cut out from a cured product of the resin from which all of the copper foil was removed by chemical etching, and a tensile mode (frequency; 1;
0 Hz, temperature rise; 5 ° C./min) and the glass transition temperature (T
g) was measured. In addition, a test piece was cut out from a cured product of the resin from which all of the copper foil was removed by chemical etching, and a tensile test of the cured product was performed at 25 ° C. using an Autograph AC-100C (manufactured by Shimadzu Corporation). The elastic modulus and elongation were measured. The results are shown in Table 2.

[0066]

[Table 2]

As can be seen from Table 2, the resin film using the modified cyanate ester resin of the present invention is obtained by reacting a cyanate ester with a specific monohydric phenol.
It was confirmed that the dielectric properties in the GHz band, particularly the dielectric loss tangent was low.

Next, a resin film with a copper foil was produced using each of the resin varnishes for curable films of Examples 1 to 4 and Comparative Example 1, and the properties as multilayer materials for printed wiring boards were evaluated.

Example 5 The resin varnish for a curable film of Example 1 was applied to a roughened surface of an electrolytic copper foil having a thickness of 18 μm using a comma coater (manufactured by Hirano Techseed Co., Ltd.), which is a type of bar coater, and coated with a resin. C. for 2 minutes to prepare a resin film with a copper foil having a resin layer thickness of 60 to 70 .mu.m.

(Example 6) The thickness of the resin layer was the same as in Example 5, except that the resin varnish for the curable film of Example 2 was used instead of the resin varnish for the curable film of Example 1.
A resin film with a copper foil of 60 to 70 μm was produced.

(Example 7) Resin layer thickness in the same manner as in Example 5 except that the resin varnish for curable film of Example 3 was used instead of the resin varnish for curable film of Example 1;
A resin film with a copper foil of 60 to 70 μm was produced.

Example 8 A resin layer thickness was obtained in the same manner as in Example 5 except that the resin varnish for curable film of Example 4 was used instead of the resin varnish for curable film of Example 1.
A resin film with a copper foil of 60 to 70 μm was produced.

Each of the resin films obtained in Examples 5 to 8 was excellent in handleability without resin cracking or powder dropping even when cut with a cutter knife.

Next, an inner-layer circuit board (MCL-E-679, manufactured by Hitachi Chemical Co., Ltd.) formed of a glass cloth substrate on which a surface-treated conductor circuit (copper foil for circuit; thickness: 18 μm) was formed.
(Product name), the resin films with copper foils of Examples 5 to 8 were superposed on both sides of the base material thickness: 0.1 mm so that the resin layer was in contact with the inner layer circuit. .5MPa
Under the conditions described above, press molding was performed for 90 minutes to produce a four-layer wiring board.

Comparative Example 2 Using the resin varnish for a curable film of Comparative Example 1, the thickness of the resin layer was 6 in the same manner as in the Example.
A resin film with a copper foil of 0 to 70 μm was produced. Using this resin film with copper foil, a four-layer wiring board was produced in the same manner as in the example.

The four-layer printed wiring boards of Examples 5 to 8 and Comparative Example 2 were evaluated for moisture resistance, solder heat resistance and copper foil peel strength by the following methods. Table 3 shows the results.

<Characteristics Evaluation Method> Crack resistance: All outer copper layers of the four-layer wiring board were removed by chemical etching to obtain test pieces. This test piece was
Immediately after immersion in an oil bath at 60 ° C. for 20 seconds, move to an oil bath at room temperature and perform a series of operations of immersion for 20 seconds as one cycle. Use a stereoscopic microscope to check for cracks on the resin surface every 100 cycles. And observed. This was repeated up to 1,000 cycles, and the number of cycles until cracks occurred on the resin surface was measured. Moldability: The outer layer copper of the four-layer wiring board was completely removed by chemical etching, and the filling property of the inner layer circuit with the resin (the presence or absence of voids or burrs) was visually determined. -Moisture resistance: The outer layer copper of the four-layer wiring board is completely removed by chemical etching, and put into a pressure cooker tester at 121 ° C. and 2.1 atm. The adhesion was observed.・ Solder heat resistance: 260 mm square 4-layer board with copper outer layer
The sample was floated on a molten solder at a temperature of ° C., and the time until blistering occurred was examined. -Copper foil peel strength: Measured in accordance with JIS-C-6481.

[0078]

[Table 3]

From Table 3, it was confirmed that the resin films with copper foils of Examples 5 to 8 were improved in crack resistance by adding a filler. In addition, these resins have good moldability as a multilayer wiring board material, and are obtained by reacting a cyanate ester resin with a specific monohydric phenol compound to form a four-layer wiring board using the resin film with copper foil of the present invention. Has good soldering heat resistance, and has been confirmed to have the same properties as the bonding prepreg using a conventional glass cloth as a base material.

[0080]

As described above, the resin composition of the present invention can be easily handled by a film alone, has good solvent resistance, and the cured product has a low dielectric constant and dielectric loss tangent in a high frequency band. When used as a multilayer wiring board material, it has good crack resistance, moldability, solder heat resistance, copper foil peel strength, etc., so it is used for printing used in equipment that handles high-speed digital signals and high-frequency signals related to wireless communication It is an insulating film suitable for manufacturing wiring boards, especially by the build-up lamination method. By using the resin film of the present invention, a printed wiring board suitable for high-speed computers and low loss of high-frequency related equipment can be easily manufactured. It can be manufactured.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 71/12 C08L 71/12 79/00 79/00 Z 83/04 83/04 C09D 5/25 C09D 5 / 25 109/00 109/00 163/00 163/00 171/12 171/12 H05K 3/46 H05K 3/46 BT (72) Inventor Kiyoshi Hirosawa 1500 Ogawa Oji, Shimodate-shi, Ibaraki Prefecture Hitachi Chemical Co., Ltd. F-term in the Research Laboratory (reference) 4F071 AA12 AA42 AA51 AA58 AA67 AC09 AC11 AE03 AE17 AF39 AG05 AH12 AH13 BA02 BA07 BB02 BB13 BC01 4J002 AC034 BG044 BN124 BN144 CD003 CD023 CD053 CD063 CD103 CD133 CH03X01 002 CG142 CP002 DB062 DB072 DB092 DB152 DB262 DB282 DF051 DF052 DG071 DG072 DG291 DG292 DL032 JA47 JC38 KA04 KA08 MA02 MA12 NA21 PB09 PC02 5E346 AA12 AA43 CC02 CC12 CC32 DD02 DD03 DD12 DD2 2 DD32 EE08 EE33 FF04 GG02 GG15 GG17 GG22 HH06

Claims (20)

[Claims] (A) a cyanate ester compound,
An insulating varnish comprising a resin composition containing (B) a phenolic compound, (C) a polyphenylene ether resin, and (D) a filler as essential components. 2. (A) a cyanate ester compound,
An insulating varnish comprising a resin composition containing (B) a phenolic compound, (C) a polyphenylene ether resin, (D) a filler, and (E) an epoxy resin as essential components. 3. The insulating varnish according to claim 1, wherein (D) a filler made of an elastic material containing silicon is used as the filler. 4. The method according to claim 1, wherein (D) a filler made of an elastic material containing an organic substance is used.
Alternatively, the insulating varnish according to claim 2. 5. The method according to claim 1, wherein (D) a filler containing 60% by weight or more of polybutadiene is used.
Alternatively, the insulating varnish according to claim 2. 6. The method according to claim 1, wherein (A) is a cyanate ester compound represented by the formula [1].
An insulating varnish according to any one of the above. Embedded image 7. The insulating varnish according to claim 1, wherein (B) is a monohydric phenol compound represented by the formula [2]. Embedded image (Wherein, R ₄ and R ₅ represent a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms, and may be the same or different, and n is a positive integer of 1 to 2) 8. (A) Cyanate ester compounds 10
The insulating varnish according to any one of claims 1 to 7, wherein 4 to 30 parts by weight of the (B) phenol compound is blended with respect to 0 parts by weight. 9. The insulating varnish according to claim 1, further comprising a modified cyanate ester resin obtained by reacting (A) a cyanate ester compound with (B) a phenol compound. (A) 2,2-bis (4-cyanatophenyl) propane or 2,2-bis (3,5-dimethyl-4-cyanatophenyl) methane as the cyanate ester compound An insulating varnish according to claim 1. 11. As (B) a phenolic compound, p
The composition according to any one of claims 1 to 10, further comprising-(α-cumyl) phenol.
An insulating varnish according to any one of the above. 12. The polyphenylene ether resin (C) is an alloyed polymer of poly (2,6-dimethyl-1,4-phenylene) ether and polystyrene or styrene-butadiene copolymer, wherein the poly (2,6- 12. The insulating varnish according to claim 1, which is a polymer containing 50% or more of (dimethyl-1,4-phenylene) ether. 13. The insulating varnish according to claim 1, wherein the resin composition further contains a metal-based reaction catalyst. 14. The metal-based reaction catalyst according to claim 13, which is one or more selected from 2-ethylhexanoate, naphthenate and acetylacetone complex of manganese, iron, cobalt, nickel, copper and zinc. An insulating varnish as described. 15. A resin film obtained by semi-curing or curing the insulating varnish according to claim 1. 16. A method for manufacturing a multilayer printed wiring board, comprising: laminating the resin film according to claim 15 on a circuit board on which a circuit has been formed, and then forming a circuit on an outer layer surface to make electrical conduction with an inner layer circuit. 17. A resin film with a metal foil, which is obtained by applying the insulating varnish according to claim 1 on a metal foil and semi-cured or cured. 18. A multilayer printed wiring board which, after laminating the resin film with a metal foil according to claim 17 on a wiring board on which a circuit has been formed, forms a circuit on an outer layer surface and makes electrical conduction with an inner circuit. Production method. 19. The insulating varnish according to claim 1 is applied to a circuit board on which a circuit has been formed, the solvent is removed by heating and drying, and the film is formed and cured to form a circuit on the outer layer surface. A method of manufacturing a multilayer printed wiring board for making electrical conduction with an inner layer circuit. 20. An insulating layer using the insulating varnish according to claim 1 is provided on a circuit board on which a circuit has been formed, and further, a circuit on an outer surface is formed on the insulating layer. A multilayer printed wiring board with conduction between the inner layer circuit and the outer layer circuit.