JP2005281394A - Resin composition, metallic foil with resin, and multilayer printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition from which a multilayer printed wiring board having high heat resistance of hardly causing separation and crack by a thermal shock test such as a cold-and-hot cycle, a low thermal expansion and flame retardancy can be produced; to provide a metallic foil with a resin, using the resin composition; and to provide the multilayer printed wiring board. <P>SOLUTION: The resin composition usable for forming a resin layer of the metallic foil with the resin comprises a cyanate resin and/or a prepolymer thereof, an epoxy resin substantially free from a halogen atom, a phenol resin and an inorganic filler. The metallic foil with the resin is obtained by attaching the resin composition to a metallic foil. The multilayer printed wiring board is obtained by overlaying the metallic foil with the resin on one or both surfaces of an internal layer circuit board, and subjecting the overlaid product to hot pressure forming. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin composition, a metal foil with a resin, and a multilayer printed wiring board.

  In recent years, with the demand for higher functionality of electronic devices, etc., high-density integration of electronic components, and further high-density mounting, etc. are progressing. Compared to the conventional technology, miniaturization and high density are progressing. As a measure for increasing the density of such printed wiring boards, a build-up multilayer wiring board is often employed (see, for example, Patent Document 1).

A general build-up wiring board is formed by stacking an insulating layer made of resin only and having a thickness of 100 μm or less and a conductor circuit. In addition, as an interlayer connection method, a laser method, a photo method, or the like can be used instead of conventional drilling. These methods achieve high density by freely arranging small-diameter via holes, and various build-up interlayer insulating materials corresponding to each method have been proposed.
However, in the method using the build-up multilayer wiring board, since the interlayer connection is made by fine vias, the connection strength is lowered, and in some cases, when subjected to a thermal shock, cracks and disconnections are caused by the stress generated from the thermal expansion difference between the insulating resin and copper. There was a problem that occurred.

  Furthermore, these build-up multilayer wiring boards are often required to have flame retardancy. Conventionally, in order to impart flame retardancy, it has been common to use halogen-based flame retardants such as brominated epoxy in epoxy resins. However, since dioxins may be generated from halogen-containing compounds, the use of halogen-based flame retardants has been avoided along with the recent serious environmental problems. A system has been required.

Japanese Patent Application Laid-Open No. 07-106767

  The present invention relates to a resin composition capable of producing a multilayer printed wiring board having flame resistance as well as high heat resistance and low thermal expansion that do not cause peeling or cracking in a thermal shock test such as a thermal cycle, and the like. The present invention provides a metal foil with resin and a multilayer printed wiring board.

Such an object is achieved by the present invention described in (1) to (8).
(1) A resin composition used for forming a resin layer of a metal foil with resin, which is a cyanate resin and / or a prepolymer thereof, an epoxy resin substantially free of halogen atoms, a phenol resin, and inorganic A resin composition comprising a filler.
(2) The said cyanate resin is a resin composition as described in said (1) which is a novolak-type cyanate resin.
(3) The resin composition according to (1) or (2), wherein the epoxy resin is a mixture of a first epoxy resin and a second epoxy resin having a weight average molecular weight larger than that of the first epoxy resin. .
(4) The resin composition according to (3), wherein the first epoxy resin is an aryl alkylene type epoxy resin.
(5) The resin composition according to (3) or (4), wherein the second epoxy resin has a weight average molecular weight of 5,000 or more.
(6) The resin composition according to any one of (1) to (5), wherein the phenol resin is an aryl alkylene type phenol resin.
(7) A metal foil with a resin, wherein the resin composition according to any one of (1) to (6) is supported on a metal foil.
(8) A multilayer printed wiring board, wherein the resin-coated metal foil according to the above (7) is heated and pressure-molded on one or both surfaces of the inner circuit board.

  The present invention relates to a resin composition comprising a cyanate resin and / or a prepolymer thereof, an epoxy resin substantially free of halogen atoms, a phenol resin, and an inorganic filler, and a resin using the resin composition It is related to metal foil with a multilayer and multilayer printed wiring board, and it is possible to manufacture a multilayer printed wiring board having flame resistance as well as high heat resistance and low thermal expansion that do not cause peeling or cracking in a thermal shock test such as a thermal cycle. It can be done.

Below, the resin composition of this invention, metal foil with resin, and a multilayer printed wiring board are demonstrated in detail.
The resin composition of the present invention is a resin composition used for forming a resin layer of a resin-coated metal foil, and is a cyanate resin and / or a prepolymer thereof, an epoxy resin substantially free of halogen atoms, phenol It contains a resin and an inorganic filler.
The resin-attached metal foil of the present invention is characterized in that the resin composition of the present invention is supported on a metal foil.
The multilayer printed wiring board of the present invention is characterized in that the resin-coated metal foil of the present invention is overlaid on one or both sides of the inner circuit board and heat-press molded.

First, the resin composition of the present invention will be described.
The resin composition of the present invention contains a cyanate resin and / or a prepolymer thereof. Thereby, a flame retardance can be improved.
The method for obtaining the cyanate resin and / or its prepolymer is not particularly limited. For example, the cyanate resin can be obtained by reacting a cyanogen halide with a phenol and prepolymerizing it by a method such as heating as necessary. it can. Moreover, the commercial item prepared in this way can also be used.

Although it does not specifically limit as a kind of cyanate resin, For example, bisphenol-type cyanate resin, such as a novolak-type cyanate resin, a bisphenol A type cyanate resin, a bisphenol E-type cyanate resin, a tetramethylbisphenol F-type cyanate resin, etc. can be mentioned.
Among these, a novolak type cyanate resin is preferable. Thereby, while being able to improve heat resistance by the increase in a crosslinking density, a flame retardance can further be improved. The novolak-type cyanate resin is considered to have a high proportion of benzene rings due to its structure and easily carbonize.
The novolak type cyanate resin can be obtained, for example, by reacting a novolak type phenol resin with a compound such as cyanogen chloride or cyanogen bromide. Moreover, the commercial item prepared in this way can also be used.

Here, as the novolac type cyanate resin, for example, those represented by the following general formula (I) can be used.

Although it does not specifically limit as a weight average molecular weight of the novolak-type cyanate resin shown by the said general formula (I), It is preferable that it is 500-4,500. More preferably, it is 600-3,000.
If the weight average molecular weight is less than the lower limit, the mechanical strength may be lowered. Moreover, when the said upper limit is exceeded, since the cure rate of a resin composition will become quick, preservability may fall.

In addition, as said cyanate resin, what prepolymerized this can also be used. That is, a cyanate resin may be used alone, a cyanate resin having a different weight average molecular weight may be used in combination, or a cyanate resin and a prepolymer thereof may be used in combination.
Here, the prepolymer is usually obtained by, for example, trimerizing the cyanate resin by a heat reaction or the like, and is preferably used for adjusting the moldability and fluidity of the resin composition. is there.
Although it does not specifically limit as a prepolymer here, For example, what a trimerization rate is 20 to 50 weight% can be used. This trimerization rate can be determined using, for example, an infrared spectroscopic analyzer.

In the composition of the present invention, the content of the cyanate resin is not particularly limited, but is preferably 5 to 50% by weight of the entire resin composition. More preferably, it is 10 to 40% by weight. Thereby, the said characteristic which cyanate resin has can be expressed effectively.
If the content of the cyanate resin is less than the lower limit, the effect of increasing the heat resistance may be reduced. On the other hand, when the above upper limit is exceeded, the crosslinking density increases and the free volume increases, so that the moisture resistance may decrease.

  In the resin composition of the present invention, an epoxy resin containing substantially no halogen atom is used. Thereby, while being able to provide heat resistance and a hardly thermal decomposability, the film formability at the time of manufacture of resin-coated copper foil and the adhesiveness to an inner layer circuit board at the time of manufacture of a multilayer printed wiring board can be improved. Here, the phrase “substantially free of halogen atoms” means, for example, that the content of halogen atoms in the epoxy resin is 1 wt% or less.

Although it does not specifically limit as content of the said epoxy resin, 10-60 of the whole resin composition
It is preferable that it is weight%. More preferably, it is 15 to 50% by weight.
If the content is less than the lower limit, the effect of improving the film forming property and adhesion may be lowered. Moreover, since content of cyanate resin will decrease relatively when the said upper limit is exceeded, low thermal expansibility may fall.

  In the resin composition of the present invention, the epoxy resin is preferably a mixture of a first epoxy resin and a second epoxy resin having a weight average molecular weight larger than that of the first epoxy resin. Thereby, when manufacturing a multilayer printed wiring board, coexistence of the embedding property of an inner layer circuit and flow control can be aimed at.

First, the first epoxy resin will be described.
Although it does not specifically limit as said 1st epoxy resin, For example, a phenol novolak type epoxy resin, a bisphenol type epoxy resin, a naphthalene type epoxy resin, an aryl alkylene type epoxy resin etc. are mentioned. Among these, aryl alkylene type epoxy resins are preferable. Thereby, a flame retardance and moisture absorption solder heat resistance can be improved.
Here, the aryl alkylene type epoxy resin refers to an epoxy resin having one or more aryl alkylene groups in the repeating unit, and examples thereof include a xylylene type epoxy resin and a biphenyl dimethylene type epoxy resin. Among these, a biphenyl dimethylene type epoxy resin is preferable. As the biphenyldimethylene type epoxy resin, for example, those represented by the following general formula (II) can be used.

  The n of the biphenyldimethylene type epoxy resin represented by the general formula (II) is not particularly limited, but 1 to 10 is preferable, and 2 to 5 is particularly preferable. If it is less than this, the biphenyl dimethylene type epoxy resin will be easily crystallized, and the solubility in general-purpose solvents will be relatively lowered, which may make handling difficult. Moreover, when more than this, the fluidity | liquidity of resin will fall and it may become a cause of a molding defect.

The weight average molecular weight of the first epoxy resin is not particularly limited, but is preferably 4,000 or less. More preferably, it is 500-4,000, Most preferably, it is 800-3,000.
If the weight average molecular weight is less than the above lower limit, the resin-coated metal foil may be tacky. Moreover, when the said upper limit is exceeded, solder heat resistance may fall.

  Although it does not specifically limit as content of the said 1st epoxy resin, It is preferable that it is 5 to 50 weight% of the whole resin composition. More preferably, it is 10 to 35% by weight. Thereby, especially moisture absorption solder heat resistance can be improved.

Next, the second epoxy resin will be described.
Although it does not specifically limit as a 2nd epoxy resin, For example, a phenol novolak type epoxy resin, a bisphenol type epoxy resin, a naphthalene type epoxy resin, an aryl alkylene type epoxy resin etc. are mentioned. Among these, bisphenol type epoxy resins are preferable. Thereby, the adhesiveness with the metal foil used by the metal foil with resin, and the inner layer circuit of a multilayer printed wiring board can be improved.

The weight average molecular weight of the second epoxy resin is not particularly limited, but is preferably 5,000 or more. More preferably, it is 5,000-100,000, Most preferably, it is 8,000-80,000.
If the weight average molecular weight is less than the lower limit, the effect of improving the film-forming property of the resin-coated metal foil may be lowered. Moreover, when the said upper limit is exceeded, the solubility of an epoxy resin may fall.

  Although it does not specifically limit as content of the said 2nd epoxy resin, It is preferable that it is 3 to 30 weight% of the whole resin composition. More preferably, it is 5 to 20% by weight. Thereby, the film-forming property at the time of metal foil addition with resin especially, and adhesiveness with the inner layer circuit at the time of multilayer printed wiring board preparation can be improved.

In the resin composition of the present invention, a phenol resin is used.
Although it does not specifically limit as a phenol resin here, For example, a novolak type phenol resin, a resol type phenol resin, an aryl alkylene type phenol resin etc. are mentioned. Among these, it is preferable to use an aryl alkylene type phenol resin. Thereby, moisture absorption solder heat resistance can be improved further. Moreover, the crosslink density can be controlled and the adhesiveness between the resin composition and the inner layer circuit can be improved by a combination with the cyanate resin, particularly a novolac type cyanate resin.

Although it does not specifically limit as said aryl alkylene type phenol resin, For example, a xylylene type phenol resin, a biphenyl dimethylene type phenol resin, etc. are mentioned. As the biphenyl dimethylene type phenol resin, for example, those represented by the following general formula (III) can be suitably used.

Although n of the biphenyl dimethylene type phenol resin represented by the general formula (III) is not particularly limited, 1 to 12 is preferable, and 2 to 8 is particularly preferable. If it is less than this, the heat resistance may decrease. Moreover, when more than this, compatibility with other resin may fall.

Although it does not specifically limit as a weight average molecular weight of the said phenol resin, It is preferable that a weight average molecular weight is 400-18,000. More preferably, it is 500-15,000.
When the weight average molecular weight is less than the above lower limit, the metal foil with resin may be tacky. Moreover, when the said upper limit is exceeded, compatibility with another resin component may fall and a uniform resin composition and hardened | cured material may not be obtained.

Although it does not specifically limit as content of the said phenol resin, It is preferable that it is 1 to 40 weight% of the whole resin composition. More preferably, it is 3 to 20% by weight.
Heat resistance may fall that content is less than the said lower limit. Moreover, when the said upper limit is exceeded, the characteristic of low thermal expansion may be impaired.

In the resin composition of this invention, an imidazole compound can be contained as a curing catalyst.
The imidazole compound is not particularly limited, and examples thereof include 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2, 4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- (2'-undecylimidazolyl) -ethyl-s-triazine, 2, 4-diamino-6- [2'-ethyl-4-methylimidazolyl- (1 ')]-ethyl-s-triazine and the like can be mentioned.
Among these, an imidazole compound having two or more functional groups selected from an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a hydroxyalkyl group, and a cyanoalkyl group is preferable, and in particular, 2-phenyl-4, 5-dihydroxymethylimidazole is preferred. Thereby, while being able to improve the heat resistance of a resin composition, a resin layer can be made low in a thermal expansion coefficient and a low water absorption.

  Although it does not specifically limit as content of the said imidazole compound, 0.1 to 5 weight% is preferable with respect to the sum total of the said cyanate resin and an epoxy resin, and 0.3 to 3 weight% is especially preferable. Thereby, especially heat resistance can be improved.

  The resin composition of the present invention contains an inorganic filler. Thereby, improvement of low thermal expansibility and a flame retardance can be aimed at. Moreover, an elastic modulus can be improved with the combination of the said cyanate resin and / or its prepolymer (especially novolak-type cyanate resin) and an inorganic filler.

Although it does not specifically limit as said inorganic filler, For example, a talc, an alumina, glass, a silica, mica etc. are mentioned. Among these, silica is preferable, and fused silica is preferable in that it has excellent low expansibility.
The fused silica has a crushed shape and a spherical shape, but a spherical shape is preferable. Thereby, the compounding quantity in a resin composition can be increased, and favorable fluidity | liquidity can be provided even in that case.

Although it does not specifically limit as an average particle diameter of the said inorganic filler, It is preferable that it is 0.01-5 micrometers. More preferably, it is 0.2-2 micrometers.
When the average particle size of the inorganic filler is less than the above lower limit, when preparing a resin varnish using the resin composition of the present invention, the viscosity of the resin varnish is increased. May affect the workability of the. If the upper limit is exceeded, phenomena such as sedimentation of the inorganic filler may occur in the resin varnish.

Although it does not specifically limit as content of the said inorganic filler, It is preferable that it is 20 to 70 weight% of the whole resin composition. More preferably, it is 30 to 60% by weight.
If the content is less than the lower limit, the effect of imparting low thermal expansibility and low water absorption may be reduced. Moreover, when the said upper limit is exceeded, a moldability may fall by the fall of the fluidity | liquidity of a resin composition.

  Although it does not specifically limit in the resin composition of this invention, It is preferable to contain a coupling agent further. Thereby, since the wettability of the interface between the resin and the inorganic filler can be improved, the heat resistance, in particular, the hygroscopic solder heat resistance can be improved.

  Although it does not specifically limit as said coupling agent, 1 or more types of coupling agents chosen from an epoxy silane coupling agent, a titanate coupling agent, an aminosilane coupling agent, and a silicone oil type coupling agent are used. It is preferable to do. Thereby, especially the wettability of the interface of resin and an inorganic filler can be improved, and heat resistance can be improved more.

  Although it does not specifically limit as content of the said coupling agent, It is preferable that it is 0.05-3 weight part with respect to 100 weight part of inorganic fillers. If the content is less than the above lower limit, the effect of coating the inorganic filler to improve heat resistance may not be sufficient. Moreover, when the said upper limit is exceeded, the bending strength of metal foil with resin may fall.

  In addition to the components described above, the resin composition of the present invention can contain additives such as an antifoaming agent and a leveling agent as necessary.

Next, the resin-coated metal foil of the present invention will be described.
The metal foil with resin of the present invention is obtained by supporting the above-described resin composition of the present invention on a metal foil. Here, the method of supporting the resin composition on the metal foil is not particularly limited. For example, the resin composition is dissolved and dispersed in a solvent to prepare a resin varnish, which is applied to the metal foil and dried. Examples thereof include a method, or a method in which a resin varnish is applied to a substrate and dried to produce a resin composition film formed from the resin composition, and this is bonded to a metal foil.
Among these, a method in which a resin varnish is applied to a metal foil and dried is preferable. Thereby, the metal foil with resin which does not have a void and has uniform resin layer thickness can be obtained easily.

  In the metal foil with a resin of the present invention, the thickness of the layer composed of the resin composition is not particularly limited, but is preferably 10 to 100 μm. More preferably, it is 20-80 micrometers. Thereby, when manufacturing a multilayer printed wiring board using this metal foil with a resin, while being able to fill and shape the unevenness | corrugation of an inner-layer circuit, suitable insulation layer thickness can be ensured. Moreover, in the metal foil with resin, it is possible to suppress the occurrence of cracks in the resin layer and to reduce powder falling during cutting.

  Although it does not specifically limit as a metal which comprises the metal foil used for the metal foil with resin of this invention, For example, copper and / or a copper-type alloy, aluminum and / or an aluminum-type alloy, iron and / or an iron-type alloy etc. Can be mentioned.

Next, the multilayer printed wiring board of the present invention will be described.
The multilayer printed circuit board of the present invention is formed by heating and press-molding the above resin-coated metal foil on one or both surfaces of the inner circuit board. Specifically, the metal foil with resin of the present invention can be obtained by superimposing the metal foil with the resin on one side or both sides of the inner layer circuit board and heating and pressing it using a flat plate press or the like.
Although it does not specifically limit as conditions to heat-press form here, Implementing at the temperature of 140-240 degreeC and the pressure of 1-4 MPa is preferable.
Further, the inner layer circuit board used when obtaining the multilayer printed wiring board is preferably, for example, that a predetermined conductor circuit is formed by etching or the like on both sides of the copper clad laminate and the conductor circuit portion is blackened. Can be used.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

The raw materials used in Examples and Comparative Examples are as follows.
(1) Cyanate resin A / Novolac type cyanate resin: “Primaset PT-30” manufactured by Lonza Corporation, weight average molecular weight 700
(2) Cyanate resin B / Novolac type cyanate resin: “Lima set PT-60” manufactured by Lonza Corporation, weight average molecular weight 2600
(3) Epoxy resin A / biphenyldimethylene type epoxy resin: Nippon Kayaku Co., Ltd. “NC-3000P”, epoxy equivalent 275, weight average molecular weight 2000
(4) Epoxy resin B / bisphenol A type / F type mixed epoxy resin: manufactured by Japan Epoxy Resin Co., Ltd. “Epicoat 4275”, weight average molecular weight 57000)
(5) Phenol resin / biphenyl dimethylene type phenol resin: “MEH-7851-3H” manufactured by Meiwa Kasei Co., Ltd., hydroxyl equivalent 275
(6) Curing catalyst / imidazole compound: “2-phenyl-4,5-dihydroxymethylimidazole” manufactured by Shikoku Kasei Kogyo Co., Ltd.
(7) Inorganic filler / spherical fused silica: manufactured by Admatechs Co., Ltd. “SO-25H”, average particle size 0.5 μm
(8) Coupling agent / epoxysilane coupling agent: Nippon Unicar Co., Ltd. “A-187”

<Example 1>
(1) Preparation of resin varnish 35 parts by weight of cyanate resin A, 12 parts by weight of epoxy resin A, 8 parts by weight of epoxy resin B, 5 parts by weight of phenol resin, and 0.1 parts by weight of curing catalyst were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.

(2) Manufacture of resin-coated metal foil The resin varnish obtained above is dried on the anchor surface of an electrolytic copper foil having a thickness of 18 μm (manufactured by Furukawa Circuit Foil Co., Ltd., “GTSMP-18”) using a comma coater device. The subsequent resin layer was coated so as to have a thickness of 60 μm, and this was dried with a drying apparatus at 150 ° C. for 10 minutes to produce a resin-coated metal foil.

(3) Manufacture of multilayer printed wiring board On the front and back of the inner layer circuit board on which the predetermined inner layer circuit is formed on both sides, the resin layer surface of the metal foil with resin obtained above is overlaid, and this is vacuum-pressed Using the apparatus, heat press molding was performed for 2 hours at a pressure of 2 MPa and a temperature of 200 ° C. to obtain a multilayer printed wiring board.
In addition, the following were used as the inner layer circuit board.
Insulating layer: Halogen-free FR-4 material, thickness 0.2mm
Conductor layer: copper foil thickness 18 μm, L / S = 120/180 μm, clearance holes 1 mmφ, 3 mmφ, slit 2 mm

<Example 2>
Cyanate resin A 25 parts by weight, cyanate resin B 10 parts by weight, epoxy resin A 12 parts by weight, epoxy resin B 8 parts by weight, phenol resin 5 parts by weight, and curing catalyst 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high speed stirring device to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

<Example 3>
45 parts by weight of cyanate resin A, 8 parts by weight of epoxy resin A, 5 parts by weight of epoxy resin B, 2 parts by weight of phenol resin, and 0.1 parts by weight of curing catalyst were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

<Example 4>
Cyanate resin A 22 parts by weight, epoxy resin A 18 parts by weight, epoxy resin B 12 parts by weight, phenol resin 8 parts by weight, and curing catalyst 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

<Example 5>
Cyanate resin A 20 parts by weight, epoxy resin A 20 parts by weight, epoxy resin B 10 parts by weight, phenol resin 10 parts by weight, and curing catalyst 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

<Example 6>
Cyanate resin A 15 parts by weight, epoxy resin A 12 parts by weight, epoxy resin B 8 parts by weight, phenol resin 5 parts by weight, and curing catalyst 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 60 parts by weight of an inorganic filler and 0.3 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

<Example 7>
Cyanate resin A 35 parts by weight, cyanate resin B 10 parts by weight, epoxy resin A 12 parts by weight, epoxy resin B 8 parts by weight, phenol resin 5 parts by weight, and curing catalyst 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 30 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

<Comparative Example 1>
60 parts by weight of cyanate resin A and 0.1 parts by weight of the curing catalyst were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high speed stirring device to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

<Comparative Example 2>
35 parts by weight of epoxy resin A, 15 parts by weight of epoxy resin B, 10 parts by weight of phenol resin, and 0.1 parts by weight of curing catalyst were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high speed stirring device to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

<Comparative Example 3>
Cyanate resin A 45 parts by weight, epoxy resin A 25 parts by weight, epoxy resin B 20 parts by weight, phenol resin 10 parts by weight, and curing catalyst 0.1 part by weight are dissolved and dispersed in methyl ethyl ketone to prepare a resin varnish having a solid content of 50% by weight. did.
Using this resin varnish, a resin-coated metal foil and a multilayer printed wiring board were obtained in the same manner as in Example 1.

  The characteristics of the metal foil with resin and the multilayer printed wiring board obtained in the examples and comparative examples were evaluated. The results are shown in Table 1.

The evaluation method is as follows.
(1) Glass transition temperature After two metal foils with resin are laminated with the resin layer sides inside, this is heated and pressure-molded at a pressure of 2 MPa and a temperature of 200 ° C. for 2 hours using a vacuum press apparatus. The entire surface of the copper foil was etched to obtain a cured resin. A sample of 10 mm × 30 mm was collected from the obtained resin cured product, and the temperature was raised at 5 ° C./min using a DMA apparatus (TA Instruments), and the peak position of tan δ was defined as the glass transition temperature.

(2) Linear expansion coefficient After two metal foils with resin are overlapped with the resin layer side inside, this is heated and pressure-molded at a pressure of 2 MPa and a temperature of 200 ° C. for 2 hours using a vacuum press apparatus. The entire surface of the copper foil was etched to obtain a cured resin. A sample of 4 mm × 20 mm was collected from the obtained cured resin, and measured by raising the temperature at 10 ° C./min using a TMA apparatus (TA Instruments).

(3) Flame retardance The copper foil of the multilayer printed wiring board was etched on the entire surface and measured by UL-94 standard and vertical method.

(4) Formability The entire surface of the copper foil of the multilayer printed wiring board was etched, and the presence or absence of a molded void was visually observed.

(5) Moisture-absorbing solder heat resistance A 50 mm x 50 mm sample was taken from the multilayer printed wiring board, and the entire surface on one side and 1/2 copper foil on the other side were removed by etching. This was treated with a 125 ° C. pressure cooker for 2 hours and then floated in a solder bath at 260 ° C. for 180 seconds with the copper foil face down to check for blistering and peeling.

Examples 1 to 7 are a resin composition of the present invention containing a cyanate resin, an epoxy resin substantially free of halogen atoms, a phenol resin, and an inorganic filler, and a metal foil with a resin and a multilayer using the resin composition. It is a printed wiring board.
Each of Examples 1 to 7 had a high glass transition temperature, low linear expansion, and good flame retardancy, moldability, and heat resistance.
In Comparative Example 1, since the cyanate resin was used, the glass transition temperature was high. However, since no epoxy resin or phenol resin was used, the heat resistance was lowered.
Since the cyanate resin was not used for the comparative example 2, the glass transition temperature fell and the flame retardance became inferior.
Since the comparative example 3 did not use an inorganic filler, the linear expansion coefficient became large and the flame retardance was inferior.

  The present invention relates to a resin composition comprising a cyanate resin and / or a prepolymer thereof, an epoxy resin substantially free of halogen atoms, a phenol resin, and an inorganic filler, and a resin using the resin composition Metal foil and multilayer printed wiring board. According to the resin composition of the present invention, it is possible to obtain a metal foil with a resin and a multilayer printed wiring board having excellent flame retardancy, high heat resistance and low expansion without using a halogen compound. .

Claims (8)

A resin composition used for forming a resin layer of a resin-coated metal foil, comprising a cyanate resin and / or a prepolymer thereof, an epoxy resin substantially free of halogen atoms, a phenol resin, and an inorganic filler A resin composition characterized by containing. The resin composition according to claim 1, wherein the cyanate resin is a novolac-type cyanate resin. The resin composition according to claim 1 or 2, wherein the epoxy resin is a mixture of a first epoxy resin and a second epoxy resin having a weight average molecular weight larger than that of the first epoxy resin. The resin composition according to claim 3, wherein the first epoxy resin is an aryl alkylene type epoxy resin. The resin composition according to claim 3 or 4, wherein the weight average molecular weight of the second epoxy resin is 5,000 or more. The resin composition according to claim 1, wherein the phenol resin is an aryl alkylene type phenol resin. A metal foil with a resin, wherein the resin composition according to any one of claims 1 to 6 is supported on a metal foil. A multilayer printed wiring board, wherein the metal foil with resin according to claim 7 is formed by heating and press-molding on one side or both sides of an inner layer circuit board.